M20 F20, Tips for making it easier

hello, im 20M and my gf is 20F. now im just gonna start off with our long distance is only ~5ish hours give or take with traffic, i also see her at least once a month sometimes twice. we're only long distance because shes at school. im basically just trying to see if there are any tips or recommendations on making things easier until the next time id see her.(typically 2-3 weeks in between but when shes home we're inseparable. we spent every single day over summer together.) we're on our 3rd year out of 4 total but it seems every time i go to visit or she comes home then has to go back, saying bye gets harder and harder. when she was leaving the first time there was the obviously long goodbye with tears and everything but after 3 days i was feeling fine again and around a week or 2 everything was as normal as it could be with her gone but my days were spent thinking about her or being extremely upset. but now, in the third year, whenever we leave its just so much harder, we basically refuse to leave and it seems it doesnt tend to get any better this time. anything is appreciated tbh. thank you