I’ve used my old heroquest stuff many a time for d&d sessions, and we always play heroquest with roleplay, in character. The straight up dungeon crawl of it makes a nice casual, improvised session.
Heroquest, by its design is excellent for a GM + single player, as well.
Dealing with this kind of thing is a multi pronged effort.
Meds can be one of those prongs. In a pinch, you can substitute a little valerian for break-through when better (read: more consistent) choices aren’t feasible. Things like chamomile tea can serve to give you a tiny bit of external reinforcement when combined with the mental focus it brings while making and drinking it.
But you gotta combine that stuff with actual coping methods, just like with prescription meds. Meds just give you the cushion to use long term methods like meditation, exercise, lifestyle changes, identifying and working around triggers, etc.
You gotta come at this kind of thing holistically (and I don’t mean the usual bullshit use of the word, I mean treating the entirety of the self)