Aw, I just read this and my heart broke for this poor bunny
I'm really glad that you reached out for help and advice though
That's a great thing.
There are many causes for a weepy eye, as you have been told. We can't diagnose, only speculate, and having a chronic condition is one of the worst case scenarios, which means it is unlikely.
I've had a bun have a tear duct flush and it cost £50 for the procedure and he's only had to have it once so far (he is two and he had it done in early May and has had no problems since). I have also had buns with conjunctivitis and that has only been in one eye, and not spread to any of my others. It really is an unknown as to what it could be because having something caught in there is also a possibility.
You don't sound, to be honest, that you're doing what is best for this bun, you sound like you're doing what is best for you.
You do sound like you didn't realise how high maintenance and costly rabbits can be, when they are well looked after, so I agree that maybe handing these two over, and then learning and researching might be the best way forward.
I completely agree with those who said the breeder is irresponsible. You trusted his judgement and took on a rabbit that did not look right. If you get any more animals in the future, only take on those with health checks (or, if buying from a private breeder then take the animals straight to the vet before home). He also has been breeding from bad breeding stock, so therefore, potentially any rabbit from his stock could have the same problems.
It is best for the rabbit to go to someone like Starlights, so that is a good place to start. Obviously, it is best for the rabbit to get vet care ASAP, but it sounds like you are not seeing that as an option, so getting her to some one who can get her that care is important.
Something else you may not be aware of is that potentially these two girls may fight as they mature and hit adolescence, so you may be faced by needing two places to house rabbits if they can't live together. Even though they are sisters, that is no guarantee they won't fight, because every rabbit has that capability, especially in puberty.
I'm really glad to know you have had a rethink on breeding
That's great
I'm sorry you have been put in this situation, and I feel sorry for these buns and really hope you can make the best choice to give these rabbits the best chance at life (which is definitely not returning her to the breeder).
I live near Colchester and know a lot about the vets in Ipswich, so if you are in this vague area then feel free to PM me and I'll try and help in any way I can.