did so bad in the exam, thinking of taking telc c1 hochschule.

I saw many people were just finished b2 and then took this exam and somehow passed it. I tried the same and it was so hard, i barely got TDN3. Do you think i should get c1.1 c1.2 course or just c1 telc hochschule vorbereitungskurs? any advice would be really good, thank you