Regrets about buying too many machines? Well I kinda regret my very first sewing machine as it turned out to be a plastic case filled with repair bills. I more regret that I didn't know to demand the repair shop show me or tell me what the issues might have been so I could avoid repeating them, or that another red flag was that they didn't know what the problem was but charged me big bills for it anyway. As for my vintage machines, no regrets. I have four right now, I have the room & didn't spend big bucks I couldn't afford on them, so I'm happy!
I do kick myself not buying some machines. There where some that I wanted and had the opportunity to buy at a great price but passed, and one I returned to the store for a design feature I detested but I found out soon after there was a cheap and effective work arround. I don't kick myself too much though, just enough to reflect on what happened and make better choices next time. My hobby enriches my life and I'm a much happier person for having these wonderful machines and you wonderful people in my life. As long as you're better off for it and it doesn't get in the way of being a healthy person you shouldn't have to change.
If you really want or need to rehome some of your machines, go right ahead. If you think you are having a bit of a groundless freakout, I'd recommend a good cup of tea, sewing on a quilt or two, and think about it latter when you feel nice and grounded.