I guess I realize that it's ok to feel not so great some days...it will pass. I usually acknowledge the feelings and don't really try to hide them behind a smile or actions I don't really feel like taking (I used to do that and it really just made me feel worse personally). It's ok to feel bad sometimes.
For me sometimes I like to just watch a mindless TV show and sometimes I talk to someone I really connect with (I never had that with my XRAH but once I left the marriage I found for the first time real friends that I connect with so that helps...and I found them in the strangest places, so for me that was about reaching out and taking a risk and some of those worked out, some didn't. But the ones that worked out have been great friends/connections...something I don't think I'd ever experienced before).
Another thing for me is I live in a beautiful area and bustling city so sometimes I just go out on the patio and take it all in and that seems to lift my mood.
Whatever is going on it will pass....and by getting out my feelings rather than bottling or masking them that actually helps me/I used to mask and bottle everything.