The most important thing that you haven’t mentioned is are they both spayed and neutered?
It’s not unusual for an existing bunny to be very angry when a new bun is brought into their territory. It’s good that you have them side by side, but make sure that they can’t nip through the bars. There should be at least a 6 inch gap.
You’re moving quite quickly though. Now that you’ve had Fudge for two weeks, I would start pre-bonding. Really the first two weeks should just allow the new bunny to settle in, with no interaction from the existing bun. This is probably why Fudge is anxious, because he moved into somewhere completely new, and went straight into being harrassed by a territorial bunny.
You can start to swap them between each others cages every other day for at least a month. THEN you can start the actual bonding in neutral territory.
You definitely shouldn’t be letting them walk into each other’s territory at this stage. That’s very likely to cause a fight, and it would be difficult for you to separate two fighting bunnies inside a hutch. You need to make sure that your bonding sessions are highly supervised, and in an open, neutral area like the bathroom floor.
I advise having a read through the bonding section under BUNNY INFO, and also reading a few people’s bonding journals so you get an idea of what to expect, how long it normally takes, and what the steps are.