That's awesome! It's a great feeling to get into a groove playing with others.

Definitely invest in a pocket digital recorder. It's always great to be able to listen back and the recording doesn't have to be studio quality made out of the soundboard. You can get something like the Tascam DR05 (http://www.amazon.com/TASCAM-DR-05-Portable-Digital-Recorder/dp/B004OA6JW0/ref=sr_1_2?ie=UTF8&qid=1388332957&sr=8-2&keywords=tascam+dr-05) for ~$70. I got it to record my daughter's piano and choir recitals. I also use it for some guitar practice.

When listening to the playback, things you thought were bad were actually fine or not as bad as you thought. You may also hear some things you thought were fine but could use some work. It's hard to really listen while you are playing in the moment, especially if what you are playing is challenging.

Keep up the great work - it sounds like you are really progressing!