Idk what to do

Ok so I’m 15 and horny like ALL THE TIME I’ve tried masturbating but I always feel really guilty afterwards and it only last 2mins max. I don’t cum or anything I just get this weird feeling and start shaking idk how to explain it. I also really don’t get any privacy, I live with my dad and older brother and they neverrr knock before coming in and my door doesn’t lock at all. My family doesn’t sleep until really late so I’m always afraid I’m going to get caught so I’m never really truly comfortable while doing it but I sooo horny(not tryna sound weird)what should I do??😭😭