I do feel that you really care about your animals, and that is commendable, but I do also wonder about how suitable you are - and your situation is - at this particular time to be responsible for them. Assuming you are a minor, your parents are actually responsible for your guinea pigs. If they will not accept responsibility, then no matter how big your heart and well-meaning your intentions, please consider giving them to someone who will fulfill every immediate and future need and who will be prepared should anything ever come up.
It is illegal to deny an animal veterinary attention if they require it, so although it may not be necessary this time, think about what will happen when the piggies really do fall ill. Are your parents going to believe that a bit of a snuffly nose needs vet treatment, or that a drop of weight also need medical attention? You either need your parents total reassurance that they will be taken to the vets at the first sign of illness, or the piggies need to be living with someone who does have this assurance.
I understand as much as the next person how hard it is to be relying on your parents, but without their support, advice and dedication to your animals as well, you're going to find it hard to give these animals everything they need at all times.
I'm sorry that this is not what you wanted to hear, but from the sounds of things thus far, your piggies need you to really, really learn hard how to look after them - and your parents too - or go to a home with more experience.