Is he cheating?

So me and my other of over 2 years, have had a few little issues throughout our relationship but I’ve always tried to get past them. I stepped into this relationship with trust issues and personal issues from a previously abusive relationship.

It all started while we were in the talking stage, met online, and connected straight away but he went to a friends birthday party and kissed his ex. He swears she manipulated him because he was wasted. He didn’t tell me until 6 days later. I still went to meet him and said yes to being his girlfriend.

Then about 6 months in I found out he had kissed his best friend (a girl but she’s a lesbian, but I still count it as cheating non the less). And that he took his clothes off at a party with all his friends. Still I blew it off and tried to get passed it.

He’s a really friendly guy, and sometimes it comes across as being over friendly. So ive complained over and over about him being too friendly at work with his female colleagues.

So he started this new job, and came home the first day and said he has the number of a girl at his work because she needed directions. So I was like “okay suppose I have to deal with it” and then he told me later on that day that she had asked him to walk her to work (from the car park they have a 10-15 minute walk). I wasn’t happy about him walking with a girl just the two of them. So we argued for 4 days straight, and I had previously arranged to stay at my best friends one night, and I knew that he had text messaged (related to work) on his phone before I left, and when I got home the next day, I noticed they had been deleted.

He swears that he deleted them and her number to not cause problems between us, but I can’t help feel like he’s doing something he shouldn’t.. he swears he isn’t but there’s no way to prove it.

I now don’t trust him at work, and I constantly am sat here worried, and not sure on what to do.

I’ve had issues as I’m physically ill with an incurable illness so I struggle with personal issues of feeling like he will leave me for someone healthier, which he swears he would never do.

Am I just be paranoid?