Jumping to conclusions?

Hey.
So I have been with this guy for a couple months and things are ok. We don’t hang out much because of how his schedule is with his child. But when we do things are good. He brought me flowers just a few days ago. But in new years after I stayed the night with him he left to go to the rest room and my phone was next to his. I hear a notification sound and I look to see if it was mine and it ended up being his. There was an unsaved number that was texting him. I’m not going to lie I kind of panicked. I can admit that. In my past I have dealt with men texting others women secretly while I’m sitting in their face. I paid those situations no mind but I stayed observant. Being chill about those situations in my past allowed more huge signs to show where I didn’t have to second guess if I was making stuff up in my head or not.
But back to him. I seen the number and my anxiety when through the roof. I even remembered the number. I tried my best to continue the day with him but my attitude was so off and unsettled. I wish I could bring it up to him but I already know he is just going to lie to me about it. Fast forward to yesterday. I ended up trying to get rid of this feeling so I called the number. Turns out it was a texting app number because of the voicemail it had. Now I’m really freaking out. I honestly feel this is a female. I really do. I’m beating myself up about it. I don’t normally snoop. The situation in my past wasn’t snooping it was literally the same thing I was taking his phone of the my charger so I can use it and I seen a whole lot. I chilled and didn’t say anything but months later more was revealed that I couldn’t deny or misinterpret. Now this situation with my current seems like it’s happening again. I really like him and I honestly mentally and emotionally can’t take another heartbreak I had time to heal from the past and I can’t do this again. I’m a older woman. He recently is gaining my trust from lying to me about women he sneaked and talked to in social media. I’m so sorry it’s long and my grammar and punctuation may be off. I really am venting and need some sound advice. I thank you all.