Autistic burnout and guilt

Hi guys this is my first time posting. I got diagnosed about a month ago after a 2 year process. I’m very happy with my diagnosis, I feel less lonely and more content with myself which is nice. However the past few months I’ve been feeling terrible mentally. I can’t sleep (been a problem all my life but sometimes is worse than others) and when I do sleep, that’s all I want to do all day. I don’t want to leave the house, I just want to disappear and be alone. Thought about taking a vow of silence which seems ridiculous haha but was a thought nonetheless! I work part time in retail, which is arguably the worst job for me. I have social anxiety disorder and bpd, and having to work with customers is hell for me. Especially when daily there is rude and aggressive people in our store. When I go in I usually have to be on the till for around 4 solid hours which is exhausting. I’ve had a few sick days lately so I can stay in bed and not have to talk to people. I feel super depressed and was thinking about taking a month off to recover and get back in a good headspace. I’m not sure how accommodating my work will be with this, and I am very worried about what my partner will think. She’s the nicest most supportive human ever, especially with my diagnosis. But any time I take off work I always feel so guilty and like I am the worst person in the world because I can’t function like a normal person. I feel like a waste of a human, because it’s such a simple thing to be working part time and a lot of people would kill for that. Do you guys ever get burnout and take time off work for it? How have your employers been about it? Is there anything you do that makes you feel less like a fraud?