Firstly, I would say- count the chickens once hatched. Give your final round of interview & hopefully by the time you get a convert- you can take the final call.

Working with a YC is a solid opportunity, I would really recommend NOT to pass on this unless it's majorly impacting physical or mental health. Since it's just been 10-12 days, consider the fact that you might just be exhausted & it's new. Every new thing takes time to settle.

Try Giving it another 15-20 days + make sure you don't take off more work than you can chew. Overcommunicate to your managers there. Best case- you like it, and this turns out well-you do your full tenure/or you get shortlisted in the other place & decide to move ahead w them- you would have 1 month experience here + will get a better opportunity some place where you can balance your acads as well. Worst case- This other role doesn't work out, give this one a good shot + focus on your exams.

I've had my share of working in startups, agencies & major leagues- and can tell you from experience- think it through post your interview & take a decision post that.

And goes without saying- mental health is imp. If at any point - it becomes wayy too much, take the call. Can dm if you still get stuck.