Auto fellacio

Right so, to start things off, this is going to be a fairly long post about my story so far and why I'm in a bad place right now. It has taken me a while to gather the balls to make a post here. Any advice is appreciated.
As stated in the title: don't read if you are very susceptible to cues. I'll be as honest as possible whilst keeping the keywords to a minimum.
My story so far
So, I'm a straight 19 1/2 year old guy. I've been PMOing since I was young... maybe I started at like 13 y.o but I'm not entirely sure. As with most users of P, it started out pretty vanilla and I watched it frequently (most of the time, daily). I never thought it was a problem, not until I was about 17 years old - when I got involved in a relationship with a girl. During this time, I PMO'd frequently and had the common erectile dysfunction issues many users get. The ED eventually passed and I haven't had a problem with it since.
I fixed my ED by committing to NoFap, though relapsing every week or so. This was better than daily usage, but I stuck with the PMO routine nonetheless, which I wish I never did.
As I got older, my 'tastes' began to evolve into more extreme categories. It's gotten to the point where I'm scared about where this addiction is taking me. It feels like I have extremely little control over my PMO addiction. It has severely affected my self-confidence and my ability to connect with other people; I feel worthless for watching (and doing) the things I do, and although THEY don't know I have this addiction, I just can't shake this feeling of low worth.
My longest streak was about 4 weeks. I felt, in a sense, normal - during this time I exercised 4 times a week, began reading more, managed a better sleeping pattern, and had cold showers daily (I recommend this). I don't know how else to explain it - It was a GOOD feeling... but at the time I (wrongly) felt like I wouldn't be losing much if I gave in to PMO again... I felt like I lost sight of WHY I am doing this challenge. I was gradually seeing what life was like without PMO, when...
Where I am now
I threw it all away. My "meh, what-the-hell" attitude led me to relapse just "to remember what I wanted to leave behind and stop PMO after one relapse". My brain rationalised my urges and led me to believe I was relapsing to remember WHY it was so bad for me, to give my NoFap journey purpose. This goes to show how having a WHY can be ONE OF THE MOST - IF NOT THE MOST - IMPORTANT THING TO HAVE during your NoFap journey. Without it, your mind will try and shoot you down; it'll be like trying to find your way through a dark tunnel without a light to guide you; and your light is your weapon against the darkness.
I digress, let me give you insight into how bad this has gotten for me.
When I relapse, its like I release all my urges that I have been fighting against for so long. This makes the dopamine hit stronger, which is worse in the long run bc it takes longer to recover. For the past few months, I have been watching BJ p. It has gotten to the point where I only watch p including a BJ in it, if not centralised around it. This, over the past months, has developed into HOCD, which in turn has negatively affected my life in MANY ways (as you can imagine).
This in turn has led me to watch more extreme things, such as BDSM. But the thing I am most worried about is my recent 'interest' (in the moment) in auto-fellacio... I'm not going to explain what that is if you don't know about it, because it f*cking disgusts me. This is where my HOCD comes into play - I know I'm straight and not bi, but PMO had led me to build an aesthetic attraction towards penis. After relapsing, I feel a wave of shame that I can't control - I don't WANT this fetish, and I know p has developed it. Sometimes I can divert my mind and beat the urges, but other times I feel helpless against my urges to PMO after getting mental images of clips I have watched in the past.
This is by far the most challenging time in my life. I have a girlfriend and don't need any other form of sexual gratification (which I'm grateful for) yet P continues to possess power over me. I also think P had made me a more envious person; making me think I can't attain success because I don't deserve it. I have since stopped exercising and getting up early because I find little reason to do so, and being someone sceptical as a person doesn't help this. As I've said, the WHY is important. I just need to solidify mine.
This is my first post and I hope some of the more experienced fapstronauts out there can lend some advice. I'm not one for feeling sorry for oneself but I know I needed to get this out in the open - I don't know what to do. Ultimately, I want to beat this, not only for myself but for others. I want to fight through this because I know if I can, I can get through just about anything else. I'll be posting updates on my progression (quitting again today), but I can't explain how powerful these urges can get.
No TLDR. Thanks for reading. You are all amazing people.