Don't know what to do :(

Hi everyone, I'm completely new to this. I read a lot of chat forums...But I've never posted before. I try to match other peoples problems to mine..And see what advice they get. I thought I'd give this a try and see if anyone can help. It's a long story. I'll try to make it as short as poss. Im 29 and Im a mum of two beautiful girls. I was with my partner for 13 years. We lived together for 9 years. The last two years of our relationship wasnt good. It's very complicated but we basically grew apart. I fell out of love for him through neglect on his part. One major thing that made me fall out of love with him was (this is very embarrassing and hurtful to me) whenever I left the house...He'd be masturbating to porn. I caught him endless times. Told him how much it hurt me. He still continued....Anyway. Last February, I met the most amazing man online. Turned out we went to school together, he was a couple of years up from me. So we didnt "know" each other back then. Turned out he only lived down the road from me. So I started seeing him behind my bfs back. I ended up falling for him in a massive way. He made me feel like I wanted to feel for years. He cuddled me all te time. Kissed me. Just everything he did was perfect. After 4 weeks, I left my bf. I let him have the house and Me and the kids moved in with my mum for 7 months. Eventually I had my own place. 16 months down the line...Things with my man are really bad :( a few months ago, I was laying in bed with him, I had my back turned reading my book and he was playing a game on his phone behind me. I turned round to ask him something and he panicked and hid his phone. I asked him what he was hiding. He lied for two hours saying he wasn't doing anything. After me going walk out (I knew he was lying. I knew he hiding something) he finally admitted that he was watching porn. He knew how I felt about it cos of my previous mishaps with it. Anyway...He explained that he felt pressured with me, that he has to have sex everyday. And sometimes he's not in the mood. So that's apparently why he did it. That all blew over...Then just when I was happy again. I caught him when he thought I was at work. This time I went mental. Threw him out of my flat. I was so gutted :( I love him so much. But I can't go through this again. We have sex everyday. The only time we don't is when I'm on my period....But I still make sure he's sexually satisfied by oral or whatever. I'll do anything for him to stop this. Which is why I make sure he's fulfilled everyday. I couldn't bear to be without him so I let him back in. He was crying, saying how sorry he was. And that he was just horny (we'd had sex 5 hours prior to this wank) Said hed never do it again cos he doesnt want to jeopardise our relationship anymore. I just can't work him out. Now, I have ZERO trust in him. Whenever he goes back to his flat on his own...I have it in my head that's what he's doing again. Then in turn...I can't even look at him when he returns. I'm nasty to him. I'm constantly worrying. I'm close to nervous breakdown. I've been doctors. I don't want pills. I've been fine since the last time...6 weeks ago. Then he went back to his today...Making an excuse that he'd left his toothbrush at home. (lame excuse) Now I can't get it out of my head. He works nights....So he went straight to work from his house. I know for a fact, that if he did. He won't be able to look at me. Now Im thinking he did go back to do that cos he was going straight to work. My mind is working overtime and I don't know what to do :'( Do I ask him straight when he gets in tonight? I don't want to go on at him, but I can't handle this. All I do in my life now is worry and stress over him. Hes promised me over and over again. Hes explained to a point where i feel so much better. But now cos its been a while since the last time...Im worried hes got complacent again. I wont be able to tell if he has or not cos of him being at work. Should i just ask him? If he admits he has tho. I dont know what im supposed to do with this relationship. Everything else is perfect. Hes ruined everything. Hes ruined the trust. I don't know if it will ever come back. With my ex it wasn't so upsetting in the end, cos I didn't care for him anymore. But I adore this man and don't want to leave. But i can't live with someone that has this problem again. Itll be the end of me. What should I do? :(((((( Sorry the post is so long. I haven't put in half the details of it all and it's still long.