I agree with what's been said above, but you are not entirely responsible for this issue you are in.
Your mom was irresponsible to get you the piggies and then a puppy without the thought of research into the needs of both entirely different animals.
I'm saddened that you are struggling with this decision, in my mind I would find a compromise and no Piggie "dislikes" cuddles you just needed to allow them time to trust you hun. Lots of love, talking, bonding and spending time sharing their world...
Can you do that for them? Do you have the time? (my son is 15 and makes time in between studies and social time). Can you make time? I'm sure you could...
You clearly do care, if you didnt you wouldn't be here. Nor would you purchase food and bedding from your own money...
Please don't just give up on them just because you don't think you can cope... try talking to family (not just your mom) ask for advice from close friends. You are young and maybe a friend can look after them for you? That way you'll still see them? But you are able to share responsibility...
Please, just be gentle on yourself and think long and hard. Whatever you do, don't sell them. They could end up in the wrong hands. In future, also let this be a lesson learned that sometimes no matter how much we "want" a pet... it isn't always for the right reasons.
God bless x