That's fair; David Foster Wallace isn't lighthearted.
My wife was nervous about getting into DFW too - she studied Tense Present in undergrad and knew about the suicide and depressive substance abuse - so I started her on a BIWHM audiobook while we were on a flight 2 weeks ago. She got a taste of some of the weirder character biographies and DFW's metafictional style, which intrigued her. I think the most challenging short from that series is #6 ("soft" subscription paywall, couldn't find a .pdf).
Then I asked her to read A Supposedly Fun Thing I'll Never Do Again, which might be his funniest short piece but still hits with the hallmark agoraphobic/dissociative anxiety that's in all his stuff.
Thing is, DFW perceived broken-up types. He wrote those characters unnervingly well, and it feels like exposure if you self-identify as much as he did - makes it difficult to extricate.
Take care of yourself. Glad to hear you're coming out of it rather than heading in.