Is this normal or just an anxiety thing? 18+ only

I posted the other day and I'm still panicky and nervous around my girlfriend. It all started over a week ago with the first panic attack I've ever had while at the store with her. I looked over during it and saw her face during it. A day later a thought popped in my head that I should "break up with her." I fight the urge every day as it is not something that I want. I don't want to give up on her but the more I fight it the more my body seems to get stressed and anxious. As it stands right now my back is going crazy, tense as anything along with a tight feeling in my stomach and chest. It's causing me so much distress. Is this normal?

A little backstory I used to be in love with this girl for months, I would nit pick every text, seeing if she was online or waiting for a reply or text from her CONSTANTLY just to find out I was nothing, she treated me so horribly I kind of forgot how it felt to be loved, I work so hard on something that was a waste it was hard to just “nudge it off” we are complete strangers now. But not to long after I have met this girl a real girl with morals a life, respectful looks at me when I talk and listens to me. Real interest. But of course how I’m wired is to question is this real, we don’t talk 24:7 like the last girl so I thought is this love then if we don’t talk constantly? I didn’t know any better of course, until our first date where we clicked even more and more, and then the second then the third then the fourth, why am I typing this, well it’s because I still don’t feel enough even though I get letter after letter LOVE letters reassuring me yet nothing changes I love this girl but I’m scared to love her fully because what if she just leaves what if she’s lying, I love her so much and she is truly a good person, yet she has no idea how much I cry for her because I feel as if I’m failing her daily, I give her flowers, notes, good dates, really real conversations everything I need in a girl, and what I love the most is the little moments where I truly find myself loving her with all my heart for a few seconds, truly the best feeling ever where I know she loves me back and cares for me and appreciates the things I do for her but then poof there I go second guessing it, and sometimes I feel scared I wanna run away from everything because I’d rather run before I get hurt then get hurt again , but I don’t wanna feel this way I want her we can build a true connection if I allow it but how do I allow it after years of never truly loving someone for real for real, the only love I know is toxic yet I’m not toxic and neither is she, so I need a break from short form content or even music I’m willing to change if it makes my life as a whole more positive it’s just some night I think to myself am I truly enough what can I do to be better and then that sends me spiraling and then not doing anything, yet I believe I do enough for her MORE than enough I treat her super well like a queen, but the dreams I have, I dream she leaves and I’m left feeling empty more empty then ever to the point where I get up at TWO am checking my phone to make sure she didn’t ghost me or she didn’t die. It truly shows me if she does leave that’s the feeling I will feel in that moment and it is terrible the most gut wrenching thing ever and yet when I see her I forget what I was sad about her smile and everything yet when I’m alone it like I forget everything I become a whole different person, my parents and friends can tell I’m happier since I’ve met her, my energy is back but they are right but at the same time they are wrong I wish I can be with her all the time and I wish she would reassure me more but who am I to judge when she has no idea I just want to let go and love her like those little moments I get when I truly do and it’s not like I don’t like her I do constantly but it’s just that I don’t feel enough even though I am enough like we don’t text constantly throughout the day and with my past experiences I believe if you like someone you text them daily but that’s not true I text her morning, goodnight, and we check in on how our days are and of course randomly messages to is it truly just me who thinks like this I believe so hopefully she thinks that’s enough because it genuinely is enough for me but I worry about how she feels constantly should I tell her how I’m feeling or learn myself to become better?

So I know for a fact that I'm not ready for relationships. It's just not something I feel like I can do due to insecurities, self confidence, anxiety, and self esteem getting in the way of that. It's something that's always on my mind due to fomo and societal norms. I know I would like one but I haven't found any other reasons beyond the biological want. There's a woman that I really do like spending time with and I kept thinking of trying to chat with her more just as a friend to hang out and just get to know her more. Everytime I've seen her it's been a great time and we get along really well. We click on a lot of things and have big interests in common. I'd be lying if I said I didn't think of her as a romantic partner but I just know that's not something I can do. Is it disingenuous to try and be friends with her despite having this on my mind time and time again? This is the one thing I could never find myself getting over.