Eroge/galge is probably the worst medium to seek these kinds of protagonists as the vast majority are focused on romance and writing a hikki loser who gets a gf is probably too much even for the average otaku to suspend his disbelief. You'd probably be much better served by books. A lot of Russian and Japanese novels especially have suicidal or reclusive characters.
I can't think of any VN's that fit your exact criteria besides the usual answer of Chaos;Head but a couple I can think of with protagonists who have at least some 'wizard' traits or are self-hating (unfortunately most are untranslated) :
Hatsukoi 1/1 (translated) : Protagonist has friends but he's a loser with virtually no hobbies, is stupid, and has an inferiority complex at points
Pure Mail (untranslated) : Protag is a reclusive student in middle school who spends all his free time in online chat rooms or playing games
Tenshi no Inai 12-gatsu (untranslated) : Edgelord protag, experiences self-hate and has no real interests outside of smoking cigarettes, extremely pessimistic view on life
Boku ga Tenshi ni Natta Wake (untranslated): Protagonist isn't interested in love (although there are routes, but I think most of them only have sad endings). Majority of the novel is also focused on other characters in relationships, most of which turn sour.
Kimi ga Nozomu Eien (untranslated): This one's kind of questionable because the protag has friends, but he does experience self-hate and has a bit of an inferiority complex and suffers from depression at certain points, especially after the prologue>>29541
Those are pretty specific requests and I doubt there's much to meet your requirements. You could try finding nukige with ugly fat fucks mind controlling succubi into fucking them I guess.
Closest thing I can think of from what I've played is Sorceress x Alive which is an isekai story where the protagonist was kind of a loser in his original world and hated by his childhood friend, but gets transported to a world of magical duelists and becomes coach for a team of succubi competing in a tournament. Not translated though.