・・・!!

It's been a month since I started school… and I still don't have a single friend. That's super bad. At this rate, middle school all over again!!

Literal

Enroll-[and-て] 1-month... still one-person [even-も] friend [subject-が] don't-exist [that-ってのは] too-bad. At-this-rate, middle-school [gen-の] second-dance is!!

A monologue of rising panic. ってのは is the colloquial contraction of というのは ('the fact that X is' / 'X is'). 一人も~いない is the standard Japanese 'not a single one,' with counter + も in a negative clause. やばすぎる combines やばい ('bad / dangerous / too much') with the excess-suffix ~すぎる. 二の舞 is a classical idiom from Noh theater, literally 'the second dance' — meaning 'to repeat someone else's mistakes' or 'do the same thing again.' 二の舞を演じる is the fuller form; 二の舞だ here is the compressed everyday usage.