Been dealing with similar issues - every time I take time for myself I get this overwhelming sense of guilt, like I should be busying myself with more work or whatnot; even to the point where I have full-blown panic attacks when I’m not near anything I can work from like a cellphone or laptop.
In my case, though it’s mostly due to a pre-existing combination of general anxiety disorder and major depression.
I would suggest talking to a professional just in case, it doesn’t hurt to know what you’re dealing with and learn how to work around it - at the very least they may be able to prescribe something to ease the stress and help you get better quality sleep. I mention this because a common symptom of depression is oversleeping or not sleeping enough. There’s a difference between getting enough sleep and getting enough rest.
Also, as others mentioned, you may want to look into gradual lifestyle changes like adjusting your diet or exercise routine; and (if applicable) try not to stay at work later than necessary - if you absolutely have to work outside normal hours (not recommended), see if it’s possible to do so from home - work environment makes all the difference for many.
Another thing: unhealthy workplace competition. Makes it way too easy to be self-critical and can quickly get out of hand. Think about your relationships with your colleagues and bosses, whether or not they make work better or worse for you and how you feel about working with them.
Apologies for the wall of text, hope this helps at least a little bit.