Cirrus my BPD king
https://www.mangago.me/read-manga/cloud_1/
Classic, but MC has OCD
https://www.mangago.me/read-manga/ten_count/
Omg....... how could I forget............... I'll never forgive myself.......
Bottom has clear ASPD signs..... VERY CLEAR....................
https://www.mangago.me/read-manga/die_in_my_arms_kaizen_scan/
some of yall already mentioned a lot of good ones so lemme add more:
Red mansion (hes a fucked up weird little guy, anxiety, delusion of suspicion, among other things.)
Healer (the mc has so many issues, BDD, compulsive cleaning, formication, somatic delusion, bro is a medical diagnosis)
Love murder basketball (PTSD and DID. interestingly the former begets the latter. love the overall depiction. good rep. also the story is so solid. my PEAKEST PEAK.)
Between the lines (Dohu, my autistic king. also Juheon having AvPD(?) which hurts my heart so)

Tell me names of BL you read with characters have disorders/illness.