How do you trust again?

Please tell me... how can you trust again if you find out that everything was a lie? How can you trust again after finding out that when they were texting you “I love you, I’m in it for the right reasons” you find out that they where sexting with another girl that he knew for about 2 years before he met me and we’ve been together for 2 years now?

***He never actually cheated***

How can you even be the same again without finding a fault in EVERYTHING... if he is watching t.v and a sex scene comes on, or even if it’s just a pretty girl in shorts on tv k get mad I turn the channel I fast forward it, I can’t leave his sight (literally) because I feel first chance he gets, he will do it again... I couldn’t even work peacefully when I did have a job, I tried to get a job that matches his schedule so when he is home we can be together!. And even when he is at work... he’s flirt before (before he met me) with women in his job that are still working there, once there’s an attraction, there’s always that sexual thinking I believe. I am driving myself crazy but i am a dumbass and i love him!!! I’ve talked to a therapist but nothing seems to help! Can anyone give me a good word of advice please???

Update: the reason for me being jealous of girls on tv is because he used to watch ALot of mistresses (domination) videos on YouTube... he used to have “sessions” through chat so to me that’s digitally getting turned on... I know it sound ridiculous!. On another note, it’s not EVERY SHOW I have a problem with only when they show sex scenes or too much skin that I get mad. And I’m ok with watching porn when we are together.