relationship issues (emptiness/bpd)

my partner has bpd. we’ve been together for four years in a long distance relationship. before we started dating, he was struggling with a phase where he felt completely empty & he turned to bad things (like drinking) to cope. after we got together, he stopped drinking. currently, for a month, these empty feelings came back and he stopped talking to me. he texts me here and there and apologizes for making me feel sad but tells me that he can’t feel anything (including love for me). him drinking was a really really big thing within our relationship & a really big promise that he made to not drink. when we talked a few nights ago, he told me that he had been drinking a little/train jumping and all sorts of dangerous things because they made him feel. i want him to find better and healthier ways to cope. he’s not open to therapy and says that everyone he goes to tells him that “it’s biological” and that he “doesn’t produce the hormones to feel”. i really don’t know what to do. he says that taking medications will change him as a person. i’m proud of him for only drinking a little as compared to the daily drinking he did the last time this happened. i asked him if he wanted to break up and he said “i’m not breaking up with you, you make decisions like that”. he has always been really against breaking up/drinking. but, he did end up drinking to cope. so, i’m scared he’s going to leave me too, especially because i am so attached to him. i want him to know that i’m not going to give up on us and that i’m always going to support him. he’s too deep into this empty feeling and isn’t listening to me when i try to make him find healthier coping mechanisms (like therapy). i get really worried because he goes days without texting and i don’t know where he’s at/what he’s doing. i asked him if he saw a future with me and he said “i don’t know” which i understand because he’s unable to feel. i asked him if he would see a future with me later on and he also replied that he “might not be the same person anymore. what if my personality disorder kicks in?” he left after that, so i was confused. did he mean that these empty feelings would prolong for a longer period? did he mean that he would start drinking/doing bad things to cope like he used to? did he mean that things wouldn’t be the same between us ever again? i’m really confused. i want to be there for him really bad but it feels as if i’m hurting my mental health in the process. it’s hard for me to look through old pictures/messages and see that nothing is the same anymore. that he doesn’t show me the love/care that he used to. i know that he’s only this way because of the emptiness that he feels and that normally, things wouldn’t be this way. but, it’s also hard for me to know that he’s hurting his health and there’s nothing i could do about it except hope that he isn’t doing anything bad. it’s really hard to know that he might potentially not want me anymore. i know he’s super against breaking up, but it’s a scary thought that he might leave. it’s scary to think about that all that we once had may be gone. of course, i want to work on rebuilding what we had after this phase passes regardless of what happens after. but i also want him to get help. is he saying he doesn’t see a future with me because he genuinely doesn’t see one anymore or because of the empty feeling he feels? and when he feels again, are things going to go back to normal? i feel really stressed and confused. i just want things to go back to the way they were. i want to take a healthy approach to this situation and let him focus on himself and focus on myself until he feels again (while staying in a relationship). but after he feels again, i’m really scared to think about what he meant by “i might not be the same person again”? i would like things to be how they were and for us to come out stronger. the purpose of the healthy approach was so that i could handle the situation easier in the future when he felt empty again (of course i’m still scared of getting really attached to him because i don’t want to be hurt when it happens again but i wanna try this so i’m not hurt as bad as i was this time). but i don’t want him to leave me/not see a future with me anymore. and it’s killing me to not know whether that’s because he’s empty or whether he genuinely doesn’t see a future with me anymore (especially because we’re at our worst & he still is saying that he won’t leave me). any suggestions as to what he should do and what i should do?