This has been what I do with mine. Most of it is pretty fucking "well duh" type stuff, however working with people to hold you, and you hold yourself, accountable for making progress in these ways. The part of having someone to hold you to account, this is often where a therapist is the most useful. However, in this situation, this isn't an option, so you need to reach out to others.
Take your meds. If you need meds, but can not currently access them due to finance issues, there are sources out there that may be able to help. This is not often easy to navigate, but it may be something that saves you.
Try any method you can find, that is from a reputable source, to keep your sleep on a schedule, and get at least 6 hours per night. This is way more important than many wish, but generally everyone knows it is vital to health, including mental health.
Make yourself accountable to someone for daily improvement progress - eg find a friend, family member, online gaming buddy, whatever, that you report to, on a routine basis, to report the regularity of maintaining these routines. This means whatever you need to do to keep your living space clean, and in order, routine exercise, adherence to a healthy diet, maintaining the framework to keep yourself on track, like keeping your phone calendar up date, keeping lists of chores/errands you need to do, working on maintaining a hierarchy of needs (most immediate things to do, and most important), etc. This is the big one though, this person is allowed to criticize you in your failings on this, and you need to take that criticism, and use it as a call to focus on these areas. You may need more than one person willing to help. If you are isolated, there are online groups for these things. No this isn't a great alternative, but it is better than nothing, and living in despair.
You need to audit your behavior. You need to make a record of the things you do that are mentally taxing, and thus can harm your mental health. Do you spend all day, every day, at work, or stressing about work? You need to find a place you can vent this stress, and look for advice on how to disengage with work enough stop burn out, but still do what is expected. If what is expected is just too much, you need to recognize it, and work on finding a lower stress income. Do you doom scroll? Well look into apps that help you regulate the time you spend online. Also, audit your experience with the platforms you engage with. If you find one is mostly something that adds to your stress, depression, despair, etc. work on just cutting that out completely. Look at your personal relationships, and really try to assess whether or not your relationships are healthy, if not, how can they become healthy? If there is not foreseeable way to make it healthy, go low-contact, pilot no contact. If your daily life has any improvement because you no longer maintain contact, then it is time to drop them.
Social activity. This will depend greatly on how much socializing, and what kinds, you can handle, etc. This one is much more tricky, especially since anxiety, anhedonia, and other negative aspects of your mental health really affect how hard this is. However, you need to work on getting some sort of in person social contact. It needs to be regular, and I don't mean like all the time, but that there is a routine set-up for it. Local hobby groups, activities at the local library, publicly held events you may attend, try to work out a specific time period where you, and at least one friend/family member, can spend that time together doing an agreed upon activity.
Do things that allow you to put your thoughts into more of an order than they may currently be. This could be a journal, personal blog, etc. Just something where you can dump your brain, look at what came out, and apply some structure to it.
Spend time outside. Be it with people, or alone, just force yourself to spend time outside, especially in places you can see nature, see green, etc. If you just sit there observing it, it will help to maintain wellness. This is subtle, and takes a while, however it does have a real impact.
There is more, and I can ask my therapist, when I see her this week, for resources for all this, and I can update with what she says, if she is willing, which I do not see why she wouldn't be.
