Is there an easy way to keep track of how many measures you're playing in music?

I’m in this band right now with a few friends, and I haven’t really experimented with time signatures until this point in time.

So for me it’s pretty difficult to play something in 5/8 for about 12 measures. So on top of counting out the time signature, I’m trying to count out in my head how many times I’m playing, but I always manage to get lost.

Is there an easier way of doing this?
Or perhaps the more I play it, the more comfortable I’ll get?
I just don’t want to continue to keep winging what I play. ha
Just looking to see if anyone has any different method of doing this.