I hear you. I got really burned out constantly working on stuff and throwing money at my race car just to keep it on track and not actually going any faster. for the money I was spending, the car should be several seconds/lap faster than it was.
Started my daughter in karting 2 yrs ago- and my son yesterday-- and I'm having so much fun with them, I don't miss racing much myself. I get to go and play with them and all of my cars have been sitting ignored for months and I just don't care..