Making a Difficult Decision: Should I Go on Disability?

I'm hoping for opinions from any outside source - one that doesn't worry about the financial or personal aspects of this. I have a great job, with a great boss working from home. However, despite that, I can't properly get my work done. My concentration is shot, sitting in the same position for more than a few minutes hurts, and I have pains in my hands every time I type. I was just diagnosed with Fibromyalgia a week ago, so are still working to find proper treatment, but I've been having these issues for months and I'm behind on my work because of it. My boss hasn't said anything about it, but I've always been hard on myself when it comes to work. Being behind stresses me out, feeling like I'm making others make up for me stresses me out. I end up with increasing stress laying in bed on a weekday because, despite being behind, it is pointless for me to sit down in pain and get nothing done. In addition to the fibromyalgia, I have PTSD, PCOS, Hashimoto's, Anxiety and then a few "smaller" problems like TMJD. I have been considering going on disability. Obviously I haven't been forced to stop working yet, but that is only because I have such a good boss. My job is pretty much the easiest it could be and I still can't keep up. I hate telling my husband just how bad things are with work because he worries so much about finances and I feel guilty because he works hard. I've spoken to my mother about it, but she's always had the "if you don't keep working things will just get worse" mindset. I have disability insurance, and would hopefully be able to get on SSDI. With both of those I should still make 80% of my salary even on disability. I don't know what to do. Do I keep pushing myself in hopes things get better? Do I stop working so that I can focus on my health more? What if I stop working but they deny disability? I'm so conflicted. If any of you are on disability, what was the "I can't work anymore" trigger? How do you determine that point? I feel like if, as a 29 year old, I went on disability everyone would think I was just lazy since I don't have a visible disability.