It's all in your head. You can still play HR just fine, you just have a mental block. Have some confidence in your play. If you play bad call it quits, get some sleep, make sure you are eating healthy etc. Don't play when you are feeling bad and stop comparing your results. You're just making things worse by telling yourself you suck because you've done better before. Some days you'll play better than others. Chalk exceptionally good or exceptionally bad plays up to variance. The more you tell yourself that you are bad, the more it will actually become true. You probably just had a bad couple days after playing DT for a week, let it get to you psychologically, and it's all been a downhill spiral from there.
Take omgforz for example. He has barely played for 6 months, had to change his tablet area because he simply can't play on full area anymore, and can't play half the maps proficiently that he used to be able when he was playing actively. When he started "relearning" this game a few weeks ago he wasn't belittling himself over this and his aim etc have been steadily returning.
As another example, look at WWW. WWW barely plays this game these days and it's quite evident by the fact that he can barely stamina over 200bpm. He just takes it for what it's worth and plows right on forward whenever he comes back. He'll come back a shadow of his former self maybe having played offline occasionally and within a week of being active set the next top pp score (ie. defenders HR), or fc ice angel HR on the 2nd try. Sure it might take playing active for longer than that if he wants to do crazy shit like he used to but it's all in the mentality.
If all you ever do is tell yourself you suck or tell yourself you aren't getting better than you never will get better and you always will suck. If you want to improve then don't tell yourself you suck. Tell yourself that you suck now but you'll be better tomorrow, and even better the day after.