I don't trust my husband

So my husband and I have only been married for one year. I truly love him but I'm scared we aren't going to work out. So about 3 months ago I found out he had an account for a dating app! that he had recently made (2 months before I found out) I confronted him and he was lying about it saying he had it for years... etc but I knew it was only 2 months old so he finally admitted it and said it was only for "porn" but that he had to pay so he didn't use it.. I still don't believe it but he got rid of it. So about a month ago I found a cigar wrapper in his pants while doing laundry.. I don't mind him smoking. if he wants to smoke fine. I don't care but what upsets me is that he didn't tell me. I've known him for 4 years now and NEVER did he ever smoke until now. He said he was cold so he smoked it to warm him up. So that was the second thing he tried hiding from me. Recently we had went to pay his phone bill and the girl there was being wayyyyy to friendly with him. Right in front of me! She just ignored me the whole time so safe to say I did not like her since. I had this feeling that something was not right. Well I come to find she asked my husband if his boss was hiring. So she gave him her number and luckily his boss didn't hire her. Our 1 year wedding anniversary was about 2 weeks ago and we had went to celebrate so while we were having dinner he gets a snap from her! He then just puts his phone up. So obviously something is going on. So I confronted him and he told me she was nothing. That she was just saying congratulations. So I made him delete her but they became friends on Facebook. I've talked to him and told him if he wants someone else or if he's tired of me to just talk to me but don't keep doing things behind my back. He just said no I want you . You're my one and only.. blah blah blah.. but I just feel like there is no trust anymore and I don't think I can survive more of this. I don't think I'm a bad wife at all and sometimes I feel like he doesn't appreciate everything I do for him. By the way to make things worse I found out I have a pituitary tumor around the same time he started doing all of this so finding a out about all of this has been very hard for me. Sorry for the long post. I had to let it out. I don't know what to do. Any advice would be appreciated. thank you for reading