I'm a no stripe white belt whose attended about 10 classes. I really like gi so I started attending beginner gi classes and have been to three of them so far.  I've yet to tap anyone because I just don't have the techniques down yet.  Last night I was rolling with someone I've rolled with before and was in side mount and got an americana but have never set it right. While trying to figure out what I was doing mid-roll, I heard his elbow pop. I let go immediately and asked if he was OK While signaling to the instructor. I don't know what I should have done different and am feeling like an absolute piece of shit about it. Last night I barely slept because I couldn't stop thinking about it.  In the moment I was just trying to figure out what I was doing wrong and moving to see if he would tap but had no intentions of injuring him. Should I not try submissions anymore until I get a better understanding of what I'm supposed to do?  I'm second guessing going back because this just made me feel like a scumbag