I think I've messed up, big bad

I use headphone amps. I find them really useful but I share your pain. I’ve stepped right back and now practice very correctly and very slowly.

YES! I have a Vox headphone amp and I love it! I live in an apt and although I’ve been slacking due to my company taking every spare minute of my time off learning a new computer program for work, I’m finally at a point where I can start up again.
LOVE THE VOX!

I rehearse for my bands with a very small sound board, laptop computer and headphones if other folks are around. I keep a rehearsal playlist on my computer with original keys processed up or down to my bands’ needs. I leave all of the cords needed plugged into the sound board on my desk (I use a wireless for my bass so that’s easy to add) so that I’m ready to rehearse quickly at any time. Through this setup I can play along with the songs I’m learning and clearly hear everything. That little soundboard was the best investment I’ve made towards my ability to rehearse. I highly suggest it.