It's very important to know what your priorities are. Any long term goal requires continuous work. By giving up some of the things you listed, you're giving up some long term goals and you must be certain that's what you want.
What I'm surprised by is that you're giving up social interaction. When you meet people you talk about things and you're basically giving up most of the things one can talk about. If you want to keep up with social interaction I suggest that you make some changes.
On a different note, doing just useful stuff is not a very good idea. There was a TED video on how important it is to play, but I cannot find it because there are about 10 such videos :)
Something else you can do is look for better ways to manage your time. That will allow you to not give up on some of the things you like. I don't know where you could save time from, but here are some ideas:
There are techniques to keep a consistent sleep schedule so that you don't waste time trying to get asleep.
Try making plans in your head when you have nothing else to do. If you're out and want to do something when you get home (e.g. clean your appartment), think about the exact steps you'll do on your way back so that you don't waste any time.
You could replace cooking with buying food that's already prepared (there are some good quality foods for such occasions depending on where you live).
Also, accept that you cannot be productive all the time. You probably won't be able to stick to that so allow some time waste to avoid frustration.