Hitting crosscourt backhands, for a whole 2-3 hour practice sessions, with different variations thrown in is hard. Hitting in the middle is easy. Do the things you know you should be doing, not what is easy.
Playing matches & sets might be holding you back from improving your tennis. Everyone always want to go out, warm up by hitting a few balls, and then play a set. That's only a SMALL part of improving at tennis. The BIGGEST improvements take place with daily work on weaknesses.