Is this gaslighting?

When I tell my bf how I feel about something that upsets me, he gets mad at me. If I tell him I’m upset about something he acts like im bothering him. I’ve found some messages from girls on his social media that were a little flirty from them not him but when I told him that it bothered me, he made me feel like I’m crazy and insecure. I wish I could talk to him and tell him how I feel about things but instead of listening to me he gets mad at me and says I’m trying to “fight” with him and that I’m just a crazy girlfriend.