1. Take some time off or if you want to play
2. lower your play limit
3. set up a losing limit for a session
4. Accumulate little victories to re-build your confidence (e.g., in 15/30 level, your session goal can be set as a $200 winning or even less, you can achieve it at very beginning of the session, and then you quit from the session right away).

Confidence is very very important to poker, if you lose it, you must to find it back. Good luck.