Hi @Macqua, welcome to the forum, and well done for sharing some of your story... it's never easy, but a great step. My first step at trying to sort out the loneliness that was a major part of my life for decades was an online forum like this one. I've never been diagnosed with anything... other than my GP telling me I was depressed but the loneliness... i've dealt with that, and the issues it causes for many, many years.
I can't really give much better advice than what @Jynx wrote. We do tend to convince ourselves that we have to hide our feelings and that we'll 'bombard' people if we really open up and reach out to them. Yeah, some people might then distance themselves but then you do find out who your real friends, the ones you can count one are. But your parents... there's no risk there. They'd would be worried about you and want to help you. It probably worries them a lot if they feel like you're not telling them everything. So bombard them as much as you want. They will be so relieved that you did and it will help you.
Like I said, I started with an online forum, sharing stuff about myself for the very first time. Found out that people will listen and support. That gave me confidence and I got more involved. Now I have a men's group I go to and even a board game group. To be fair I was dragged kicking and screaming to that... not because I didn't like board games, but because it was a room full of random people I didn't know and I found it very difficult to go. I still feel uneasy after about 10 meetings but I know some people there no and enjoy going, but still everytime it's that day, I feel hesitancy and doubts, but it gets a lot easier.
So you just have to keep reaching out to people, building that network around you. Eventually start to find some things in your local area to do that interest you. Just keep trying to find things to add to you life that involve other people. It can be a slow process but just keep trying and it will get easier. It can only take a small amount of people that you start to have regular contact with for those feelings of loneliness to become less overwhelming. Best of luck to you, it's not easy but you've done very well so far.