Yeah, the problem with being self-hating is that it just spirals. A bad habit that just continues for as long as you let it.

One really important thing that I've personally found really helpful is not apologizing for things that aren't my fault. Just cut it out of your vocabulary as much as you can and it'll definitely help. "I'm sorry, this is probably a stupid question but..." turns into "Wait, this might be a stupid question but." Don't apologize for being in people's way. Just move and say "whoops" or something else. Another example is "I'm sorry, could you repeat that?" and "I didn't quite catch that, could you repeat that?" etc etc etc. When you're grabbing all that blame even just verbally, your brain will feed itself that it's kind of your fault.

The other thing that's been helpful to me is directly in line with BlueCrustacean's idea. There is a book called Feeling Good that mentions a very interesting exercise. You take a golf clicker and every time you have a negative thought, you count it. This brings attention to your negative thought processes. I counted easily around 100 daily when I first started. After you've gotten good at identifying them (which dropped my count to around 70), you move onto the next step which is breaking down each of your negative thoughts. Individually. Every time you have one (it's exhausting at first but I can promise you the more you do, the better you get and the easier it will be). So for example I'll do one that I've had before. You start with one thought that you have "I am a bad person." And break it down a little. What makes you a bad person? "It's because I didn't do a very good job helping someone at work." Oh okay. So you weren't perfect this one time out of how many? Oh? That percentage is still very good. And improving. It's not reasonable to expect perfection all the time. "Well I still am a bad person" Well why is that? "Because I'm not responsible." Not responsible on what? You are very responsible when it comes to taking care of your pets and being there for your friends. "Well I've been having trouble with chores and showing up on time to things." Well those chores are because of depression and hey you still have clothes so laundry isn't even dire yet. And you show up on time to plenty of things given the right motivations. You are rarely late to work and that is something you can work on via alarms and creative thinking. Anything else? "No lol not right now." So basically you become your own best friend and give yourself the support you deserve. After a very very intensive and painful half-week, I got it down to around 15 negative thoughts a day. And eventually by the time you get so tired of berating yourself into positive thinking, you'll find it so much easier to just have the positive thought instead lol.

Last note, when I was really depressed, I often found it easier to split myself into a few different sections mentally. One of which was the "BFF" character that literally only cared for my happiness. One that was a "Teacher" so to speak. They wanted the best for me but also for me to be well functioning in the world and live a sustainable life. And the most important one, and the one in control, was me. So whenever I would have a negative thought, I would jump into BFF and love myself back into wellness. I dunno hahaha it sounds a tad strange now but I found it useful.

Best of luck!