21F & 21M LDR anxiety when parting ways

me (21F) and my amazing bf (21M) have been together for a little over 2 years now & have been doing long distance for over a year. i suffer from severe generalized anxiety disorder & have been dealing with it since i was 9. i got on medication last february when things got really bad after i returned home from visiting my boyfriend that time around. every single time we part ways (whether he leaves me or i leave him to go home) i end up having panic/anxiety attacks. he left this morning after visiting for a week & i’m going up to see him in 3 weeks for a while. yesterday i started dealing with the anxiety, and today after returning home from dropping him off at the airport it’s like a bomb exploded and i had a constant panic attack for a total of 2 hours until i fell asleep. i slept all day and after waking up the anxiety is still there. i have an appointment with my therapist tomorrow because i just don’t know how to properly handle this. it’s such a terrible & torturous feeling every time. the distance isn’t going to close any time soon and he’ll be transferring schools (we don’t know where yet) which is also giving me anxiety not knowing where he’s going to end up & how that’s going to affect me visiting him (incase he gets stuck having to share a room with someone in a dorm). does anyone also share a similar experience to me? because usually i’ll be more than fine once i get back into my routine at home, but this time it feels worse.