How do you stay consistent and hold yourself accountable?

I'm 25 and I think all my life I've had problems staying consistent. I've been in a slump lately and i can't get anything done. The only thing I've been able to stay consistent with is going to the gym and that's because I love working out. There is so many things that I wanna do and accomplish but I can't bring myself to do any of it. I've really let myself go lately and I don't know how to get back on track. Part of the reason is that i experienced a series of unfortunate events that knocked me down for a bit. First I lost my job, then i started working a job where they basically abused and took advantage of me, then I got kicked out of my apartment, I lost someone that was really close to me and the grief hit me like a truck. I've also been dealing with a lot of mental health issues on top of everything.

Yes, life has been hard lately but I think I need to stop using those things as excuses. I really want to get back on track. I want to start taking better care of myself, I want to start reading and journaling more, I want to start cleaning my apartment regularly. Most importantly I want to finish my masters thesis. I've been procrastinating on that for so long and i can't bring myself to finish it. Just thinking about everything makes me feel overwhelmed. I've always had issues staying consistent and holding myself accountable. I don't even know where to start.