Believing or overthinking?

So I'm pretty sure I have a sort of psychosis. I hear people talking outside, I hear cars pulling in the driveway, and footsteps outside my window. My boyfriend of 2 years the father of my only child tells me I'm overthinking, that my mind is playing tricks on me because I think he's outside with someone... I've caught him messaging other women 2 times in our relationship. The last time I was pregnant and told him I was leaving him. He swore he didn't mean anything he ever said to the women he was messaging and that he was in a bad place mentally. The voices didn't start when I started dating him. They happened with two previous relationships. I have a feeling the psychosis I have was drug induced. Staying up for too many days when I was younger and stupid, before my felony charge. The voices and sounds are so vivid though... I don't know if I can overthink something so intense..