A year ago I made the amateur mistake of querying like +100 agents without editing my manuscript and of course all of them ended with rejections, does that mean they will no longer accept my novel even if it is polished? should I wait for like another year and change the title of my novel?
Hi Manu!
The short answer: NO!! Your story is not ruined. Breathe. Everything is okay.
The long answer:
I've been to conference panels where people ask this question ROUTINELY, and most of the agents say the chances they would remember a query is very small... and some even go so far as to say that if the work has been SUBSTANTIALLY improved, then they're happy to look it over again.
If I were you, I would make DAMN sure that your story isn't just 'polished' but freaking AMAZING (and get a second opinion on that, btw), change the name, and THEN query again.
Post your query here because you will get amazing feedback. The big majority of those 100 agents probably didn't even request your MS because your query probably wasn't very good either. So maybe, what, 10 out of those 100 agents actually saw your writing? Which means you still have 90 agents who probably wouldn't recognize it.
This isn't good practice, btw, and should NOT be considered advice. Just saying what I would do.