Stop fighting...start loving!

Hi everyone!
I joined yesterday after googling fighting rabbits and found some of the posts really helpful. I apologise for the length of this first post in advance lol!

My buck, Toby, is 19mths, and I had him initially as a house rabbit. I moved home to my parents when he was about a year old. He started displaying disruptive behaviour, so the vet suggested I castrate him and then get him a little friend. So I got him a little girlfriend, Jemima. Not realising the time it takes for hormones to go down, I tried introducing them after a week. As she was only just 4 months, and he had only been castrated a week before...it didn't go well! He was hounding her and I had to seperate them, and have kept them this way for a month. I tried introducing them again yesterday and Jemima started attacking him. I pulled Toby out and got bit in the process by Jemima. She drew blood, so she was really going to hurt him if I hadn't got in the way!!
Their hutches are one on top of the other in the shed and they have a run which I have partitioned and they go in it for hours each day. They can see each other but can't get to one another. Jemima chases him up and down the length of the run, but he's not bothered by her, unless she provokes him.

So, what can I do to sort this out lol?
Any advice would be much appreciated!
Thanks xx

Is she spayed? I'm assuming not as she's only 4/5 months?
Does can show a lot of territorial aggression and are virtually impossible to bond until they are spayed; they also stand an 80% chance of developing uterine cancer by the time they are 3 without a spay, so it's really an essential op.
Most vets wait until the doe is 5/6 months old before spaying as it's quite an invasive operation.

Once she's spayed and recovered you can start bonding in a neutral area (somewhere neither bun has been before) to avoid either bun feeling like it's "their" area and they have to defend it. There's a wealth of info on the site about bonding and lots of people who can help you when the time comes

Everything BattleKat says is what I was going to say. It's essential both bunnies and neutered and that the introduction happens somewhere neutral.

As above & also be aware that if she is not speyed & he is so recently neutered a pregnancy can still occur.
Time is your friend!
Just hang in there & while you are waiting for both buns to be truly ready for bonding do heaps of research about bonding.

Thank you for all of your replies
I have been looking at the options of her to have a spay. She's such a lovely natured pretty rabbit and it's frustrating me that they don't get along.
I'll speak to my vet about spaying and hopefully can get them together for autumn.
Thanks again for all your help
Carys x

Not sure where you were trying to bond them, was the space neutral meaning that neither rabbit had been on this place before or that it has been thoroughly cleaned with a strong smelling substance to remove any rabbit smells.

If the space is not neutral you will naturally get 2 rabbits fighting as they are just defending their territory.