A lot has been posted about the pros and cons of prologue in other threads. You hear the same points made over and again that prologues aren't necessary, they're better done as backstory or flashback, readers skip them, and so on. But a prologue can be an effective device in the proper genre--I'm thinking Robert Ludlum's use of it to set the plot in motion, to introduce a character of whom the protagonist is unaware, etc. This works for the thriller story because it's all built on suspense, surprise, and the reader's foreknowledge of things the protag has to discover for him/herself.
I don't have a lot of respect for Ludlum as a writer, but he was a superb spinner of stories. Last year I read an award-winning literary novel whose plot hinged on tragedy that occurred in the protagonist's childhood. She keeps alluding to that event and others, but does so as she carries us along in the present. So there was no need for a prologue.
My point is that the use of prologue belongs in the hands of the adept, and since you are asking the question, I presume (perhaps wrongly) that you haven't a lot of publication to your credit. Join the rest of us, myself included, who often begin the thought process with a gripping prologue and are so taken with it that we feel compelled to keep it.
The advice to finish the book and then reconsider is well placed. Keep the prologue, but write the rest as though it weren't there, and then go back and see if it's so hang-all vital.
Good of you to ask the question. You'll get a variety of opinions, I'm sure.