I can relate to many parts of this thread. The first thing I think of is expectations. I got my first guitar with the expectation that I would be great at it. Reality set in pretty quick and I was disappointed and discouraged. I have taken breaks from playing guitar but find that I can not live without one (could probably substitute keyboard for guitar or something).
Taking a break is a good thing. Telling yourself 'never' just adds more pressure. Do what you need to do to get through today, and do the same tomorrow.
Now I have the expectation that making music is not easy, but I enjoy how I feel during and afterward. If I'm not having fun, I put my instrument down and walk away, knowing I can come back to it whenever I feel like it. Maybe it's in an hour, maybe a year, it doesn't matter. I enjoy it a lot more now, and actually have improved a ton since I am more relaxed and enjoying myself.
I was going to suggest a stand-alone recorder. In this digital age you need high computing power to keep up with everything. You clearly don't have it with that older computer. That's fine, but you should try to work around it instead of trying to make it work. You should be able to find a used recorder for not too much money. The first thing that came to mind is what people use to record live performances. The concerts I go to allow recording, so I see guys all the time with long range mics and little recorders. But this is just recording, not studio editing. Maybe you need to take a break from trying to edit since that requires computing power and software. You could try a multi-track recorder and re-record tracks or something.
One thing you can do is use libraries for internet access, maybe you can download and print PDFs or sheet music and bring it home. You might find a lot more peace by taking the technology out of your home or life. I know I am happiest when I spend the least amount of time near my computer.
I have struggled with hobbies and thought about 'quitting' - but the hobbies are mine because they express part of who I am. I can't force my brain to dislike things that I am innately passionate about. Usually when I had these feelings, it was because my expectations were too high, and mostly, it's because I was trying to make things into something they weren't (a $100,000 house will never be the Taj Mahal, a $300 import guitar will never play like a $4000 hand-made hollow body, and a slow old computer will never keep up with modern day software). When I stopped trying to make things into what they weren't, I found a lot more enjoyment in life in general.