I too am sorry for the tough decision you're having to make: it takes maturity and a big heart to put the needs of your animals first, in order to do
the "right" thing for them. Much as we try, we don't always see our future with accurate clarity...we're all human & we misjudge many things in life.
Sometimes we should have known better (& hopefully we learn from our mistakes) but many times, life just throws us a curve ball, and we have to
make some difficult adjustments. I know this is a painful choice, but when you think of the alternative, it becomes easier. Hugs!
And btw, the bigger your love for animals, the easier it is to find yourself overwhelmed...don't beat yourself up, just accept that you cannot do it all.
Also: I know 'zip' about guinea pigs, but I remember meeting some folks a while back that were hugely into them, & they said there are clubs, just
like for other animals...so you might search for that? Ask all the vet offices if they know of good leads for you too? I believe that with a little effort,
you'll find someone that makes you feel good, that your pets will be in safe attentive hands.
You might also want to ask your chosen person (or family) for a reference from their own vet, if you're the least bit unsure.