16F and 17M. (please help)

Me and my boyfriend have been in a relationship for about a year and a half, but known each other for 2 years. I know this isn’t a long time, but our relationship is pretty serious.

So, recently I met a guy online and we started talking - nothing weird, just friendly talk. I don’t have friends and I’m also autistic so I don’t pick up on cues very well so when my boyfriend read through my messages with this guy he said I was being hit on which I was shocked by. My boyfriend feels cheated on because I did it behind his back, which I understand. I have a problem with being open which I know is bad but this is the main contributor to the problem. I’ve also texted another guy before a few months back, but for the same reasons - just to be friends. Am I a bad girlfriend?