It's always easier to talk about these issues on the phone than to try to type them out via chat. Jet Blue phone wait times have been less than 30 minutes lately, so give them a call.
So I'm taking it that you want to cancel the flights? If so, and if you booked the flights as a round trip, you qualify for a full refund to your original form of payment since they changed the itinerary by several hours without your consent. When you call, just politely state that this new itinerary doesn't work for you and that you want a refund. Legally, they are obligated to do that.
If you booked the outgoing and homebound flights separately, then you are only entitled to a refund for the flight that they changed. You'll have to ask them what your options are (maybe a travel credit) for the other flight, but it's very unlikely that you'd get your money back on it if you cancel it, because the airline is not required to do that. For nonrefundable fares, airlines only have to give you your money back if they cancel the flight, or if they change the schedule to be more than a couple of hours different than it was before. My advice, if you booked the flights separately, would be to cancel the changed flight and get your refund, but keep the other flight for now & wait for them to cancel it, which they very well might. Then you could get your money back on the other flight. And if they don't cancel it, at the last minute you can still cancel and at least get the travel credit (if they're offering that for people who choose to cancel flights).
I will add that I had a round trip May 30th - June 12th flight on JetBlue that they cancelled. So that's why I wouldn't be surprised at all if that other flight of yours might end up being cancelled. Of course, because JetBlue cancelled on me, I got all of my money refunded to my credit card when I asked for that.
I made our reservations in October 2019. They cancelled the outgoing flight at 10:15 and put us on a 6:33 flight and I never got an email to let me know that.
