Is it wrong to be tripping out if your hubby "really" wants to hangout with a female from 2-3 years ago?

we were going through his Instagram together and when he went on the ❤ icon I saw that he accepted a female request and I calmly asked whose that? because I dont know his whole family so I thought it was his girl cousin but he said its "a friend from high school" in an irritated tone. something didn't feel right and I went through his phone for the 1st time and saw that he texted his best friend "so... there's this girl I really want to hang out but I havent talked to her in 2-3 years, I want to hang out with her or take her to the cheesecake factory..." I think he's going to cheat on me 💔💔💔...why? because he's told me "if you mean something to me on an important level I'll take you out to the cheesecake factory"...and that's our anniversary place. advice please. when I try to talk to him he gets irritated. now I feel like his I love yous and loyalty is fake. I don't want to get a divorce and I really love this man. please help.