Replying to I'm stuck in life and need some help/motivation

Hello fellow Newschoolers,
There is a lot to read here and I apologize, but I am asking for any kind of help!

So I'm stuck in a rut and don't know what to do. Maybe I'm just having a kind of meh day today but I feel like I'm stuck in my life and wanted some insight and advice from all you guys.

So my story starts out with summer of 2013 after graduating high school. My plan was to attend MSU in bozeman where a lot of my friends were headed but I wasn't too excited for. I then fall in love with my current girlfriend whose plan was to move out to Seattle and work and enjoy life there with one of her friends. Not wanting to break things off with her, and having family out in Seattle who was offering to house me, I decided I would move out there and find a job. I got majorly hooked up with a decent paying job as a low-voltage technician at boeing working 40 hours a week from the hours of 8pm-4:30am. Since then I've been partying and living life doing all sorts of things with my girlfriend. I should also mention that one of my friends from high school was the boyfriend of my girl's friend who was also out here. He moved out here as well and we got an apartment together and our girlfriends had a different apartment a bit of a drive away. When I wasn't hanging out with my friend, we would be hanging out with our girlfriends or the four of us would be hanging out together. So my friend and his girlfriend breakup and he moves back to montana in like January of 2014 and his girl moves back in the summer of that year.

With the option of basically free rent, I moved back in with my family out here and my girl had her own apartment. January of 2015, me and my girl decide to move in with each other. She had a lot of black mold in her apartment and was desperate to get out. I believe she was more interested in gettin out of her apartment rather than wanting to spend more time with me by moving in together. I am sacrificing $660 a month to live with her in comparison to $300 a month which I was paying my family. Also in January, I started education at Shoreline Community College to get on track in becoming an engineer with the plan to transfer to a four year college.

I know this is a lot of information, but I'm trying to provide as much details as possible. I'm about to wrap this up so stuck with me here.

Anyways, I should mention that I will turn 20 in May and my girl just turned 22 last month. My girl just went on a trip with her best friend to the Dominican Republic where she partied hard and got rowdy. I try not to get jealous of not being able to treat her to stuff like this, or even get to take her out to bars here in Seattle. I used to be upset when she went out and I would get worried about her meeting other guys. I trust her 100% and I know that she would do the right thing, but It just bothers me to know that she hangs out around guys and starts up a lot of casual conversations with them at bars. She also told me all about this group of guys she and her friend hung around while on vacation. She tells me I have nothing to worry about, and I know she didn't do anything, but for some reason I just feel wronged. Am I right to feel this way? I also feel like she is less lovey to me, but I feel like it's due to me always confronting her about these guys that she hung out with. I think she's just getting the sense that I am not confident in myself. Am I right? I love her so much and don't have anyone else out here, and this is just all stressing me out which in turn is making me less motivated in school and my job. Thank you those who took time to read this post and +k to anyone who gives me some structured feedback.