Quarter Life Crisis

So I spent two days trying to figure out who to talk to or where to post this. I really hope this is the correct place for this.

I am 20(M), in the Army, in Hawaii. Recently I have been going through some tough shit... It all began back in January when my girlfriend of 3 years ended our relationship. I slipped into a period of hopelessness and failure, at work I just acted normal. I just channeled some fake motivation to make everything look normal at work. Abut 2 weeks later I was told that I would be attending the Army Jungle Expert School and I met girl, a hostess at a restaurant. Things seemed to get better! I actually started putting myself back together and no one else, not work or my friends noticed that anything happened. So I see this girl and prep for my school, everything seemed to work itself out. She was genuinely interested in me and we had a good time just being with each other, even if we were just walking the beach. So here is where it goes downhill again... After a few weeks, we attempt to have sex twice. I could not get erect... I was so incredibly attracted to her, but I just wouldn't work. Eventually I leave for the Jungle School, I give this course everything I had. I was the only MP there... Everyone else had their friends and co workers and I was alone. I tried super hard to socialize and be member of the platoon I was assigned to. But I just didn't fit in with the crowd. I worked hard and I graduated, to return to find out she was seeing someone else...

Fuck!

I put on the almighty mask again, acted super proud and motivated. Only to go home to just lay in my bed with a seemingly endless cycle of negative thoughts. "What is wrong with me?" "Why can't I fit in?" "Why do I have problems socializing and being with others?".

Thankfully I have four amazing friends that decided to help me out. These four people became my rock, I spent nearly all of my time with them and they were people I genuinely enjoyed being around. They took me out, helped me socialize, relieved some stress. Made me feel apart of something. One of my friends PCS'd to Korea, another is getting out due to mental health problems. My two remaining friends have been continuing to help me. But it feels like a downward spiral.

I went on leave to visit family and friends back home, hoping that it would improve my condition. Only for it to make me worse! I met two amazing girls while I was home, and I know that nothing can ever happen with either of them... On top of that I spent a fuck ton of my savings and money helping out my dysfunctional and chaotic family. We are working like 80 hour weeks on the road doing law enforcement. I feel physically exhausted all the time. I feel like I'm losing relationships with my family and friends from my hometown. I get home from work everyday and sometimes the stress and anxiety is overwhelming to the point where I just lay in my bed and feel sorry for myself. I can't seem to maintain new relationships here in Hawaii other than my two close friends that remained here.

Long Story, I know. But it feels fucking awesome to vent to my computer and the internet. But here is the question:

"What do I do?"

Do I need therapy? Counseling? Why do I feel like I cannot talk openly about this with my boss or my friends? Why is it so difficult for me to socialize? Why can't I find a healthy way to manage stress? Why do I make little problems and mistakes into HUGE failures?

I appreciate the chance to finally speak my mind. Thanks Reddit.