Is he cheating on me?

So i’ve been in a relationship for 2 years with this guy and like on instagram he barely has followers so nothing goes on but on snapchat i’ve seen that one time a girl posted a picture and he sent “ 😍😍” so i questioned him and he would tell me his phone screen is all cracked and that his phone is always tripping so he must have butt dialed it but what a coincidence that it was “😍😍” right? So anyways i was getting really mad and upset i wasnt believing him so he was like if youre not gonna trust me then leave and i wanted to give him the benefit of the doubt and i was like ok like i’ll believe you whatever,. Time goes on and again i see another other girl on his “recent chats” and she sends him a picture while i’m using his phone just a picture of half her face but still wtf it pissed me off so i question him about it like who the fuck is that girl etc and he was like “idk her she randomly added me on snapchat” and i was getting mad and he was like “i cant have friends now?” And he told me they just had a casual conversation but when i click on their chat it doesnt show any messages so idk what to believe but its all suspicious to me. So today we get into a small argument and i see that he makes a new snapchat, and he hasnt even told me about it. I’m really gullible so idk but like i’m not stupid and i feel like something is going on but the other part of me just doesn’t want to say nothing to not seem crazy because what if i’m wrong and its a misunderstanding completely?? He works as a security so when hes at work hes facetiming me or he calls me and on his days off hes with me so how could he be cheating on me?

Update: i asked why he made a new snapchat and he said because he was tired of girls hitting him up but he said he doesnt really like his new snapchat username and then i asked why didnt he tell me he was making a new snapchat and he said “because i wanted to surprise you” bruh like i wanna believe him but i been gaslighted before by him which should be a huge sign and like he acts like this sweet person and always helps me be a better person etc so its hard to breakup with him like extremely hard