Depression and AuDHD, need help self-motivating
I've struggled with depression since I was a teenager, was diagnosed with ADHD at 6 and with autism at 29 (that's its own story), and the three are the world's most brutal tag-team trio when it comes to basic functioning as a human being. Despite AuDHD basically requiring routines to function, the ADHD side of my gremlin brain does everything it can to sabotage any attempts at creating one, then depression comes in cheering them both on and throws one knife into the ring.
Basically, my question is, how the hell do I motivate myself to get up and take care of my responsibilities when every single mental health website gives advice like "break big tasks down into smaller ones" (cool, now I'm overwhelmed) and "create a routine"? My fiancee, god bless her, has been incredibly supportive but is reaching her own limits and this is a last resort to find advice on my part (posting online gives me severe anxiety). I've basically gone afk in my own life, constantly on /follow and only responding or reacting, never initiating anything. I'm perfectly willing to get up and do whatever is asked but that's not exactly the type of relationship someone wants to have with the person they're supposed to marry. I am great at setting the boundary of "I don't have the spoons to talk about this right now" but I can never actually remember to bring it back up later, so "not right now" ends up meaning never. I'm in the process of getting approved for TMS, but that's not a sure thing and it's a long process. I'm in weekly therapy and take more meds every day than my grandmother.
I know I just threw a lot out there but the tl;dr of it is what are your tips for being a semi-functioning human being when you're at rock bottom?