Husband a sex addict

I've been with my husband for 15 years. 4 years ago we split because I just wanted him to realise what he had been doing (never cleaning up after himself, spending all the money, no responsibility) and I moved into a unit with our 3 kids, we still had a good relationship, would sleep together and on occasion he spent the night. One night in this time I went out got drunk and kissed a random, nothing else happened, my husband picked me up that night and we slept together. Anyway he found out and 2 months later he got a girlfriend, slept with her etc. They had been together for a month before he told me, I was heartbroken, and i begged for him to come back (even though he was still spending money, to the point of borrowing money from me, still no responsibility, lived with my brother etc.) He moved back in with me, we have been back together for nearly 2 years, we fought a lot because things hadn't changed, he's a smoker and would lie to me about it, lie about money etc. He got a job in the mines in Sept FIFO, after a few months there I was on night shift and took his tablet to work. He has hidden things from me in the past, deleted text messages from girls, taken videos of me undressing and i wasnt aware of it etc. I looked through his tablet, everything was straight, then I went to his recent purchased apps and Bigo and Livu were there, these are live chats with girls. he had deleted his account and deleted them off his account, but he had made purchases for coins, (you give people coins if you like the video) and he has been on these sites for months, but has intentionally hidden them from me. He also has videos of other girls saved in his google drive. I confronted him and He tells me he is a sex addict, and is getting help now. I just cant shake this feeling that everything is a lie, he is not the person I thought he was, and he doesn't love me like he says he does (he still tells me everyday he loves me and wants to be with only me, he always has said that) I just don't know what to do or what to believe. I had chances to sleep with other people when we were split, but I couldn't because I knew it would be the end, I couldn't bring myself to do it, even though he wasn't proving himself at all to me. I'm just confused and don't know where to go, I love him and don't want to break up our family, but I know he doesn't feel the same way (even though he is convinced he does) if he felt the same way, he would of fought for me to begin with. I don't know what I'm asking, I guess I'm just venting. Any advice would be great. Thanks