This is tmi, and fucked up - but I have ptsd from a shooting and have trouble with stuff like...loud bass and sudden bangs still. But right after it happened, I couldn't trust a fucking soul. Cause I was all sorts of messed up in the head, and I am so thankful for those that pulled me out. One being my therapist, who I found on Open Path. But either way, in time I realized that I didn't even know how to trust myself anymore because I was so fucked up. And when I worked on that, I felt like I could trust others again...to a point. Never like I used to. Because I straight used to be pure heart on my sleeve. But I did get back to being able to trust as a whole, and that helped with a lot of other things. While I am not 100% better, and might never be (idk, I just take it one day at a time) - I am like way better than I was when I was in the thick of it all.
Also it sucks you feel like you lost your dreams. But perhaps it's time to re-evaluate what that is, if it's worth pursuing or if it's something worth laying down. Because sometimes some stuff is straight up a situation of place and time and whether we like it or not - it's just worth letting go of it otherwise it drives us crazy. You sound like a realist - how you type. But also clearly a dreamer (cause you wouldn't have dreams if you weren't). So maybe figure out a way to combine the two to reconnect yourself to happiness.
As for finding friends? Eh, I used to be able to make them pretty easily. Some fall off, some don't. An ex told me she was once told by a person who is no longer with us (cancer) that people are in your life for a reason, a season, or a lifetime. I recently had to come to terms with pretty much losing my best friend. Who I grew up with, and have walked through so much life with. But he's on a different path than me, and we've just split at the seams. And there's only so much reaching out you can do, before it's just something you let go. It hurt, but I think ultimately it is what it is. Still makes me sad, but what can I do about it? There was no dramatic fight, or event or anything. He just sort of drifted off. And it is what it is.
I have heard volunteering can connect you to new folks. Back when I did (I'm focusing on my health right now so that door is closed for me) I will say that I met some cool folks but I didn't really make any deep connections so I'm not sure if that's 100% true. I do know that friends you can make online can become something far deeper. As I used to run a forum, and still stay connected to a handful of folks I met there. So perhaps that'd be the best place to start. Because it's low-commitment and high-gain if you hit it off with someone. Focus on things you enjoy and branch off from there. GL, and never forget to love yourself. Because that helps all the rest of the pieces fall together.