I’m way too frugal with my money

I don’t know if it’s because of how I grew up, since I grew up very poor living paycheck to paycheck, but I feel guilty spending my money on anything. Even after I pay for groceries, I feel anxious and upset with myself that I didn’t spend less. I constantly get angry at myself when I buy new bras or new pants for work even though I need them. I literally just ordered two bras from Victoria secret because I was able to get 20% off and free shipping and it came out to $39 and I’m now feeling that feeling of regret but it’s already to late to cancel the order.

The only time I feel fine about spending money is when it’s on my boyfriend and it’s because I love making memories with him and going on dates.

But I’ve gotten so bad to the point where I even get upset with my boyfriend when he spends his own money on video games, which is not fair to him since he does work and make more money than me and deserves to spoil himself. I just don’t know what’s wrong with me, I can’t seem to ever spoil myself. And just to put this in perspective for you guys, I have almost 16k in the bank, I’m only 18. My boyfriend and I rent a house from his mom for $250 a month. We pay for all the bills besides water. So it’s not like we need to be very cautious with how we spend our money because we are getting by really easy, but I still have that mentality that I’m poor. Like if i see my money drop too much I’ll request for more hours that week just to get back to where I was because I refuse to go below $15k