Anxiety and relationship stress

I don’t really know what to say I had my first anxiety attack back in February and since then it’s gotten much much worse I’m a teen and life is hard my dad is gone for the next 8 months and my mom has her own mental health problems so taking care of my younger sisters as the oldest is hard sometimes. I do online school and I have a job and that goes well I get good grades I make okay money and everything works out. I’ve know my girlfriend for almost 3 years we  both lived in Utah then moved to the exact same city again it was like meant to be and almost 7 months ago I asked her out it was a case of she fell first and he fell harder and it’s been great but it’s both of ours first real relationship so things are sometimes difficult. I try my hardest to make sure she’s happy. I write letters buy flowers reassure her spend time with her everything I can think of but sometimes it’s not reciprocated. I write a 4 pager letter to her and I’m lucky if I get a 2 paragraph text message and it’s hard when you feel lile your not being appreciated for what you do and we talk alot we make sure we communicate but over time I’ve become very insecure because of the lack of effort and it’s hard and that’s what started to spin out my anxiety there are times when I ask her to text me when she gets to work and just won’t text me or she stopped wearing her necklace I got her that she wore for 3 months straight or when we’re out together she prefers to talk with everyone else and I feel excluded. And the truth is she’s a great girlfriend I just it’s hard I’ve talked to her about all of this and it’s gotten a bit better. I also understand she’s not a very emotional person and that’s Jsut how things are for her so things that matter to me don’t matter as much to her. And I’ve become so insecure and that makes me anxious I’m anxious to go out because I’m scared to be left out. I don’t know if it’s exactly anxiety but I’m not really sad I Jsut feel like I don’t do enough and like when she doesn’t talk to me the whole time when we’re out I start to breathe heavy and I can’t stop moving and I have to leave because I can’t breathe and I need to break down. And every night these past 5 days has been like this I feel like the worst boyfriend ever because I have to leave whatever activity we’re at so I don’t break down in front of everyone and I talk to her about everything and it’s alot for her and it’s getting to the point where we talked tonight and she said she thought about everything and she wants to be with me and she loves me but maybe a break would be good but she also thinks that maybe it wouldn’t. I love this girl more than anything and I can’t lose her to my anxiety and insecurity’s. There’s alot going on with family too and I’m sorry this post is so long but it’s Jsut alot I can’t breathe I throw up I feel awful and I Jsut cry and cry and I need to get over this if anyone has any ideas or can message me I would really appreciate it thank you all