Rabbits Please Help! What do I do now?!

How big is their cage, how old are they, and are they both neutered?

The cage should really be expanded. Most people go by 3x6 for one but I go by 2x6 for one. If you can make a 3x6, that's a good first step.

Two boys is really iffy. A neutered male and female pair is usually less volatile.

You can try a scary car ride and longer intros before putting them together again but there is no guarantee they would work it out. You could try.

There is a wonderful website called House Rabbit Information and Care - BinkyBunny.com and there an a entire section to rabbit bonding with lots of helpful information. Some people are extremely lucky and their rabbits take to eacho ther right away, and some have a lot of trouble. I recently adopted a second rabbit and in a few months my bonding journey will begin as well.

Before you adopted the second one, was the first one in the same cage/room as they have now? That may be a cause for your problem; when the second one arrived there was no neutral territory. Try putting them in the bathroom, or a pen in the yard [be sure to supervise], or a room of the house that no one has claimed yet.