Is it time to stop forgiving him?

I am at such a loss. 
After 3 months of marriage I found out my husband had a gambling addiction and £30,000 of debt. 
After the initial shock, worry and fear I did everything to support him, professional support, paid some of his debt, took charge of finances, educated myself of gambling. Had to have my own counselling support through GamCare. 
Fast forward and over the past two years, to my knowledge as he has been caught engaging in fantasy football and buying lottery tickets. I say to my knowledge as I only know when I find things. 
Last week I went away for 24 hours, I have since found out that he had photos of horse tips and had searched for bookies twice outside of our safe banned area during this time. 
I don’t feel I am getting any understanding from him and instead he is very much playing it down, almost refusing to talk about it. He claims he didn’t go through with it but rather “playing a game in my head” I find this very worrying. As what’s the next step and next step.
I hate the constant fear I live in, only knowing something has happened when I find it yet I don’t want to be in a relationship where I need to find things out.
When caught the aggression from him is dreadful. Even after a period of time I am offered very little reassurance or safety that it will happen again. We have talked at length about safety planning but each time the desire clearly takes over. 
He does speak privately with a professional but I do question his transparency.
We have only been together 4 years and I can’t help fearing that I can’t keep doing this and is it time to walk away. The relationship is under intense pressure separate to this, his working hours are long and draining, he refuses to move jobs yet hates his job and I can see the negative effect it has on him. 
All support welcomed.