At this point, I just want to reassure Hemee that she's not done anything wrong! There's a lot of opinions being fired at you, and I have a feeling they might be a bit intimidating!
Lots of people do what you're doing, keeping a piggie and a bunny together. We're crazy about these animals, so we advise not to do it. But it is done, and it is done successfully. I still don't advise it, but have seen people who've done it without a hitch!
If you can, I'd suggest seperating them and feeding them food which is designed for their species. At the very least, perhaps you could feed them seperately, unless someone knows more about this Supa Excel Guinea forumula?!
There are lots of rabbits on RR looking for homes, perfect to keep your bunny company, and there's been recent posts about piggies looking for homes, too. Might that be an idea for you?