how to ask partner for support

Hi! Does anyone have suggestions on how to ask a partner to support you better? I am trying my hardest in my current relationship I’m in dbt I’m starting my meds again I’ve been struggling but I am trying and I’m doing a lot better than I’ve done in previous relationships although I have some bad anxiety in relation to triggering topics. I am working my on it and still have my bad days, and my partner is understanding of this. However every time I feel really bad his responses do not feel very indicative of getting it which isn’t like per say the end of the world but I told him I’ve been feeling lonely in our relationship and he was like I know it may not seem like it rn but you’re never alone with me!! And idk I love him and I know he means well but I don’t know what to do because we keep having conversations about how I don’t feel supported through my mental health moments and I emphasize that I have bpd before getting into any partnership because I can try all I want but you need to also understand that this is not just like some mild condition everything really does make or break things for me and it’s not up to him to solve them or save me but I feel really lonely and not supported by the way he says things. He’s not great with words but he doesn’t make the effort sometimes and I get really frustrated and resentful and then I feel horribly guilty because it’s not on him to fix me. So I was wondering if anyone has any concrete things they’ve done to communicate or make things work or ask for extra support from a partner. Please let me know I love him so much but I’m going crazy and I need to have this convo with him but I don’t know what changes to suggest because I can’t just be like TEXT ME BETTER like that’s so vague and I don’t want to hurt him or make him feel like I’m attacking him I just feel so sad