These are both grammatically correct:
- You’ll go back to reliving your college days.
- You’ll go back to relive your college days.
The former is rather like "I look forward to seeing you...", and "I look forward to see you" is incorrect.
Since both the reliving sentences are grammatical, does the different verb form give each example a separate meaning? Such a subtle difference in wording probably does give a subtle difference in meaning.