stop lying to people so that I can get out of problems, make myself look better, and seem more interesting

I told a friend of mine that I got a bad grade on a lab for a spelling mistake when actually I just felt like complaining about the teacher.
Told another friend of mine that I didn’t want to talk to him because my friends don’t like him, when actually I was just feeling uncomfortable.
The trick now is…to catch myself before I lie or work up the courage to admit to then afterwards.

Positive: I don’t lie to him or around him anymore.
Negative: It’s when he’s not there that I catch myself lying.

I’m not going to give you my whole sob story. It’s weak and dumb and I want out of it.