He's always watched and never seen!!!
I like playing with darkner biology worldbuilding from the perspective that there are Species of darkners (like ambyu-lances, addisons, pippins, ruddins, cuptains, etc) who have perfectly standarized biology for their species and then theres Special darkners who are one-of-a-kind whose biology is pretty much fantastical (Jevil doesn't need to eat, both him and Seam are immortal, Rouxls has no organs at all, etc). And Tenna's one-of-a-kind Cabinet Man makeup leaves him in the middle of the way where he doesn't have enough fantastical characteristics to not have to worry about anything health-related and not enough biological characteristics for specialists to know exactly what his body is doing.
Naturally, being sick or injured is a nightmare for Tenna! It's not just objectification (though there is a lot of it too) but it's also otherization, because he's not enough of any characteristic to belong to any "kind" of darkner. It's a very isolating experience in a situation that is very worrying! And in a check-up visit a doctor could just be looking at his numbers and go "well this isn't normal. But is it normal to you?" and he'll have to sigh and go "I don't know" and that's gonna be the end of the conversation. And then maybe the doctors start babbling about making estimates and doing tests and saying medical jargon he can barely keep up with and inviting other doctors from other rooms to take a look and discuss findings and all he wanted was just an answer to this new pain he's been feeling.
And this would certainly bleed into mental health professionals too. I think even in an environment where he has a kind and strong support system he'd be uneasy about seeking help from any professional regarding his mental health issues because he has no idea if the psychotherapist will just be the same as the other doctors and want to study his psyche instead of helping him figure out his traumas and feelings. Like no wonder the only guy he will be vulnerable in this way is the obsessive producer/personal assistant that he pays to do everything for him (love battat to death but lets be real i dont think this guy is a licensed therapist) and whose only goal in life is to make Tenna happy in the short term.
I just. AUGH! So many thoughts about the television. I'm glad you liked the tags it's been an idea i've been cooking up for a while