How to make sure only 1 thread is running? C++

I have an app that plays a game for me, and it required me to make a thread which constantly scans my health and moves the character to a spot, if I go under that health. When the game is finished, it starts a new one, and then it creates a new thread which scans for health. Total of 2, of the same thread. How can I make so only 1 of those threads is created?

This is the thread I’m creating:

void task1()
{
    

    while (true)
    
        {
            cout << "T1!" << endl;
            HWND hwndinGame = FindWindowA(0, ("Game")); // Updating data each loop.
            GetWindowThreadProcessId(hwndinGame, &pID);
            uintptr_t oBaseAddress = GetModuleBaseAddress(pID, L"Game.exe");
            HANDLE inGameHandle = OpenProcess(PROCESS_VM_READ, 0, pID);


            LocalPlayer = Reader.ReadVOID(inGameHandle, oBaseAddress, oLocalPlayer);
            myMaxHealth = Reader.ReadFLOAT(inGameHandle, LocalPlayer, oObjMaxHealth);
            myHealth = Reader.ReadFLOAT(inGameHandle, LocalPlayer, oObjHealth);
            posX = Reader.ReadFLOAT(inGameHandle, LocalPlayer, oObjPosX);
            posY = Reader.ReadFLOAT(inGameHandle, LocalPlayer, oObjPosY);
            std::this_thread::sleep_for(chrono::milliseconds(100));

            if (myHealth < myMaxHealth / 1.97)
            {
                Clicker.DirectInput('f');
                liveGameO.move_to_lane_noA(liveGameO.AbleToGetPos);
                Sleep(4000);



            }

            while (myHealth < myMaxHealth / 1.97 && posX < 6000 && posY < 6000)
            {

                Clicker.DirectInput('b');
                Sleep(10000);
            }

        }
    
}

This is the place where the thread is created in main:

        std::cout << "In Game! Sleeping for 10!" << endl;

        std::thread t1(task1);
        t1.detach();

        Sleep(20000);

It’s in side a while loop, so for each run through, an additional thread is created which is what I am trying to avoid, I only want one of those threads, so my app doesnt crash sooner or later 🙂

Thank you!

CreateMutexA(0, 0, "unique_mutext_name");
if(GetLastError() == ERROR_ALREADY_EXISTS) // already exist?
    return -1; // quit
// program code