1. Depending on the relationship, you will never get over the loss of a parent. It's not something anyone ever said until my mom was passing/passed, and then everyone that had lost a parent told me that in private. It's ok to be that way and from what I can tell the norm.
2. I pretty much always had upper management/executive roles previously. When I got out, I worked sorting human/animal waste and worse at a recycling plant. I dug through filth/trash with a 'pull 60 pieces of cardboard out a minute from a high speed conveyor belt' no rest metric. Now, I am back to my previous social status level. Don't get hung up where you are, keep your focus on where you want to be. When you went to the USA you didn't complain that you were 'stuck over the ocean' because you knew in a few hours you would be where you wanted to go. You are over a desolate ocean for a little while but it's a passing thing (if you keep moving, if you give up, you are a permanent castaway).
3. Anger/bitterness is just self abuse. The Universe doesn't care how you feel or what is fair. So keep your head up, stand proud, turn that energy into something productive. My wallpaper says 'Bellum Romanum' because I put all my energy into countering the indifferent/adversarial system that wants to keep me down. You are a good man, you went to care for your father when so many are too selfish to do that. That put's you in the top 5% of people easy in my book.
4. Get some exercise. If you can, to the point you almost pass out from fatigue at night. That will help clear your mind of bs made up self defeating thoughts at night. Get your anger/hostility etc out here (but don't hurt yourself). Start super slow though, you hot enough, you don't need health problems.
5. You can still find someone and start a family.
6. The fact you reached out means you don't want to end things, you just want a break from the crap you are going through. Remember that. You want a break, not an out. A break, not an out. In prison, you look to 'get space from reality' in little ways. We would plan out weekend rice bowls or burritos for weeks. Plan things out, give yourself something to look forward to. Maybe it's making cookies, maybe it's a hike somewhere new. You need something to look forward to, and actionable steps you can take to get there. We were 'making moves' when we would get vegetables out of the kitchen, we were showing we still had some control, we were 'sticking it to the man'.
7. Stop unproductive things. If you are a computer geek single male, I'm going to go out on a limb. No porn dude. Your body/soul naturally want to push you to the whole family/connection thing. Don't short circuit that drive, harness it. You will find yourself way less numb without that garbage.
8. One day at a time. No one did anything instantly. Yesterday you took two steps backwards (or more likely, life/the Universe pushed you two steps backwards), that's ok, because you have today, and today you can work towards how you're going to get one of those steps back.
9. You want community? Make it. Every single person who doesn't burn you, deserves to be in your community. You are no better than anyone else, and people are not tools to get where you want, even if where you want is just healthy. So you be that community you want for everyone else (who hasn't burnt you). You will find yourself in an amazing community before you know it. I had people make sure 'I was good' on Thanksgiving. I had people push me to relationships with my kids so that on Thanksgiving, where by default I wasn't going to bother my sone, I called him and it was an AMAZING phone call. But that's because I had people who had my back, people that have been thrown away in the eyes of others every day of their life. How many people who are yearning for community too have you just looked past/looked through? Don't do that. See EVERYONE around you. They deserve to be seen, just like you want a community to SEE you.
I see you. You took care of you family. You are awesome. You are self aware enough to know you need a hand, and humble enough/willing to be vulnerable enough to reach out here. I would 100% be willing to have you in my community of friends. Keep your head up, keep moving, process your fathers death (remember anxiety is part of our grieving process, you lost stability with the loss of a parent and part of you will be in chaos), limit anger/anxiety/porn and other unproductive use of your energy, redirect to taking a step forward today, no matter how small, see people and treat them how you wish the world would treat you (as long as they don't burn you. Write off those that do, you gave them a chance). Make simple plans so you have things in life to look forward to (for me just waffles on the weekend can be that. Dude, waffle day is a good day. And grocery day is a good day because I'm getting stuff for waffle day vs I have no money to get what I used to eat and life sucks and poor me).
TLDR - You can do this. I can see the details in your post that show you will even if you don't see them.