Reverse changes after relapse

Hello, I have big problem. I was addicted to porn for long time when I was young. I break this habit and after few years become completly free. No fantasies, no thinking about anything sexual, I had a lot of energy, I was emotionaly strong and had good focus. I was worked physicaly usually 12h per day and after I can go running, start eat healthy, I was breaking with bad habits, my libido was strong. Problem starts when guy with I was working shows mi few times porn materials at work. It was terrible and burn my dopamine receptors, but I after some time I came back to balance. I left this job because of that. In meantime my relationships with my girlfierd starts going really bad. Because of this bad things I M with not using porn twice and after second one something break with my mind and old porn fantasies comes to my mind and start burning me. I become horny angry sad stabilize fantasy comes to my mind and again. It last 3 months and nothing change exept Im weaker and weaker. My focus is really bad and I dont know how to break the cycle. I was trying cold showers, running, I have very low energy now, I am not workig. When I was breaking with porn before it was becoming better and better, now its worst and worst even Im not loking anything sexual, exept these fantasies which triggers me and sometimes its just 1 sec image, nothing long. My libido is lower and lower. Do you have any advices after that terrible relapse and how to break the cycle. I feel really dumb now. Kind regards

 

After this relapse I am not M at all (its now 77days without M). I only have sex with my gf about one per week. What is killing me its these fantasies which triggers me and I cannot control it.