Did I go too far with being cheated on?

I (31M) have always struggled with women. I didn’t get my first girlfriend that I didn’t pay for until 30. I soon learned that she was with other men as she was using me for money. I was about to leave her but my male friends talked me into staying despite this. They argued that since it took so long to get one real gf that it might be too hard to get another, and that she could stop eventually.

After 8 months though, I got tired of it regardless of what my friends said. Last night I came home to one of the regulars with her and, I’m just gonna say... he was a big man. I was so sick of him being in my own bed that I didn’t care, I grabbed my pistol just in case. I went up to my own locked door. I forced him to leave and he didn‘t wanna leave till he got his. He threatened to beat me up, and even got up to do so.

When he opened the door and started swinging (at air), I fired my gun and showed him the door. My gf ran out scared. Another neighbor even called the police and I was found to be simply defending myself against a ”violent trespasser.” Did I go too far?