Your thoughts please on my situation.?

I wish I had a healthy realationship with my mom. My dad died when I was 8. I have 2 brothers and then there is me in the middle of them. My moms been single for 11 years ( not a serious relationship ) But now she has a boyfriend for just over 2 months and she spends all her time with him. She always worked alot. She had to. So we kinda had no limits. I did somethings I wish I didnt. I just feel so alone. I guess I'm not good with being honest about my feelings. I'm scared to love and open up it's uncomfortable for me. But I'm lonely what should I do. I'm not a affectionate person and neither was my mom with us. I dont want to be that way. I'm 19 years old, I didnt finish high school. I did work for a little over a year at a pizza place when I was like 16 but I new I was getting money when I was 18 from my dad dying. A little bit over $20.000. I'm turning 20 next month and I already spent like all that money on nothing to valuable except my laptop. So I was unwise. Anyways I need to look for a job soon because I have to give my mom $200 a month and my money is running out. I guess I never had much discipline. When my dad was alive we would get the belt and he set rules and we would listen or if we didnt we would get in trouble. But I guess my mom wasnt stricted on and like spoiled us in a way and just let us do what ever but now my lifes a mess. I'm not like other teenagers. I have friends but dont talk to them much any more. I dont do to much. I'm scared to get a job. I have a GED book that I can study for and I can go for my G2 but like I feel like lifes pointless for me. I'm sad and feel I have no one really to look up to. My mom works and spends time with her boyfriend she use to make us dinner but now barely not at all, since he's been around. My life sucks. I guess what I'm asking is what do you think I should do? What's a good Idea for me? What would you do if you were me? I dont need to talk to you guys privatly lol just some suggestions would be nice. I feel like I dont matter to much