Timer running at increased speed each time I start it again

I am currently working on an app, and it has a timer in a separate view from the main ContentView(). I have realized that I am not resetting the timer each time, and since it is initialized with a binding var, the var is increasing faster than desired (add one to var every 0.01 seconds). Simply setting the var to a binding and changing it that way hasn't worked for some reason, and I have created a function that runs every time the timer fires to check if the isRunning binding var is false, and if it is, invalidate the timer. The code for ContentView is:

import Foundation
import SwiftUI
import CoreData

struct ContentView: View {
    @Environment(\.managedObjectContext) private var viewContext

    @FetchRequest(entity: Time.entity(), sortDescriptors: [])
    private var times: FetchedResults<Time>
    
    @State var startstop: String = "Start"
    @State var start: Bool = false
    @State var elapsedTime: Int = 0
    @State var timeMinutes: Int = 0
    @State var timeSeconds: Int = 0
    @State var timeMilliseconds: Int = 0
    @State var hour: Int = 0
    @State var minute: Int = 0
    @State var second: Int = 0
    @State var formattedTime: String = ""
    @State var saveTime: Int = 0
    @State var timerRunning: Bool = true
    @State var firstRun: Bool = true
    // Format date after core data fetch to allow creating NSSortDescript for date
    var body: some View {
        VStack{
            Text("Cube App")
                .font(.largeTitle)
                .fontWeight(.bold)
                .padding(.top, 4.0)
            Text(scrambles.randomElement()!)
                .font(.title)
                .fontWeight(.semibold)
                .multilineTextAlignment(.center)
                .padding([.top, .leading, .trailing])
            if start{
                Stopwatch(progressTime: $elapsedTime, isRunning: $timerRunning)
                    .padding(.top)
                    .fontWeight(.bold)
                    .onAppear{
                        timerRunning = true
                        toggleStartStop()
                    }
            }
                
            Button(startstop){
                toggleStart()
                if start == false{
                    saveTime = elapsedTime
                    stopTime()
                    elapsedTime = 0
                    toggleStartStop()
                }
            }
            .fontWeight(.bold)
            .font(.system(size: 30))
            .padding(.top, 30)
            Spacer()
        }
    }
    
    private func stopTime(){
        timerRunning = false
        print(saveTime)
        addTime()
    }
    
    private func addTime(){
        withAnimation{
            timeMinutes = saveTime / 6000
            timeSeconds = (saveTime % 6000) / 100
            timeMilliseconds = saveTime % 100
            let time = Time(context: viewContext)
            if timeMinutes == 0{
                if timeMilliseconds < 10{
                    time.time = "\(timeSeconds).0\(timeMilliseconds)"
                }else{
                    time.time = "\(timeSeconds).\(timeMilliseconds)"
                }
            }else if timeMilliseconds < 10{
                if timeSeconds < 10{
                    time.time = "\(timeMinutes):0\(timeSeconds).0\(timeMilliseconds)"
                }else{
                    time.time = "\(timeMinutes):\(timeSeconds).0\(timeMilliseconds)"
                }
            }else{
                if timeSeconds < 10{
                    time.time = "\(timeMinutes):0\(timeSeconds).\(timeMilliseconds)"
                }else{
                    time.time = "\(timeMinutes):\(timeSeconds).\(timeMilliseconds)"
                }
            }
            time.date = Date()
            
            saveContext()
        }
    }
    
    private func saveContext(){
        do {
            try viewContext.save()
        } catch {
            let error = error as NSError
            print(error)
            fatalError(error as! String)
        }
    }
    
    private func toggleStart(){
        if start{
            start = false
        }else{
            start = true
        }
    }

    private func toggleStartStop(){
        if startstop == "Start"{
            startstop = "Stop"
        }else{
            startstop = "Start"
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        let persistenceController = PersistenceController.shared
        ContentView().environment(\.managedObjectContext, persistenceController.container.viewContext)
    }
}

Note: I have excluded the array of "scrambles" as it went over the character limit, but it is only used in a text in the vstack. The code for the Stopwatch (Timer) file is:

import SwiftUI

struct Stopwatch: View {
    @Binding var progressTime: Int
    @Binding var isRunning: Bool
    /// Computed properties to get the progressTime in hh:mm:ss format
    var hours: Int {
        progressTime / 6000
    }

    var minutes: Int {
        (progressTime % 6000) / 100
    }

    var seconds: Int {
        progressTime % 100
    }
    
    var timer: Timer {
        Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true) {_ in
            progressTime += 1
            reset()
        }
    }
    
    var body: some View {
      HStack(spacing: 2) {
          StopwatchUnitView(timeUnit: hours)
          Text(":")
          StopwatchUnitView(timeUnit: minutes)
          Text(".")
          StopwatchUnitView(timeUnit: seconds)
      }.onAppear(perform: { _ = timer })
    }
    func reset(){
        if isRunning == false{
            self.timer.invalidate()
            print("invailidated")
        }
    }
    func toggleRun(){
        if isRunning{
            isRunning = false
            progressTime = 0
            print(isRunning)
            timer.invalidate()
        }else{
            isRunning = true
        }
    }
    func fetchTime() -> Int{
        return progressTime
    }
}


struct StopwatchUnitView: View {

    var timeUnit: Int

    /// Time unit expressed as String.
    /// - Includes "0" as prefix if this is less than 10
    var timeUnitStr: String {
        let timeUnitStr = String(timeUnit)
        return timeUnit < 10 ? "0" + timeUnitStr : timeUnitStr
    }

    var body: some View {
        HStack (spacing: 2) {
            Text(timeUnitStr.substring(index: 0)).frame(width: 10)
            Text(timeUnitStr.substring(index: 1)).frame(width: 10)
        }
    }
}

extension String {
    func substring(index: Int) -> String {
        let arrayString = Array(self)
        return String(arrayString[index])
    }
}

struct stopwatch_Previews: PreviewProvider {
    static var previews: some View {
        Stopwatch(progressTime:.constant(0), isRunning: .constant(true) /*firstRun: .constant(true)*/)
    }
}

Could somebody help me reset the timer each time and fix the issue?