Finding it so hard to be away from my girlfriend in long distance M21 and F21 is

So it’s the summertime, and we’ve met at university but live in different cities. We’ve been dating for close to three years, and we’ve done long distance summers before. But recently, as I’ve fallen even more in love with her, dealt with personal demons, and have been more expressive in my emotions, I’ve noticed how much I hurt to not be around her. When I see her again, everything lights up and I’m so so happy. But when I’m not with her, I just have so many bouts of sadness and just loneliness and I wish she was with me.

I know it’s healthy to miss someone, but this kind of sadness feels like so much, like too much for me to handle at times. I want to establish more safety within myself and build that trust with myself, but I always find it hard when we’re doing long distance because all I want is my girlfriend.

Do you guys have any advice about this and what to do?

TL;DR I am struggling without my girlfriend in long distance