BIG HUGS
I call it 'grieving indigestion' when you have so much loss in a short time that you cannot keep up with processing it. It takes all of us hard as each bond is unique and the loss hurts - and you are feeling very much like a walking raw wound.
I have several times lost three or four piggies in very close succession, sometimes in a matter of just days or a month. Even when your head knows that any of your piggies can develop a problem out of the blue and that problems come in batches and never nicely spaced out, it is still horrible to bear when you are in the thick of it. You can cherish any piggy that lives a long life span as a wonderful boon; but you can never bank on it. I have certainly lost about the same number of young piggies to all sorts of sometimes freak issues.
What counts is that you make the time with them a happy one for them; guinea pigs don't have a concept for a set life span. They measure their life in happy todays and being loved and well looked after. You and your partner are certainly doing that in spades! Your piggies couldn't have been luckier to have found you.
Give yourself time and be easy on yourself. You have to grieve as much as you love; it is so much harder when it is all so unexpectedly ripped away from you much earlier than you expected. There will be a time - once you are past the immediate hurt - when you realise just how much your pets are still with you in your memories and your heart because they are an integral part of your life and will always remain that way. The river of your life may move on and touch other lives, but those that have shaped its flow will always remain part of it and will be carried on with you in the current.
If you find that it helps you to look at old pictures and videos to remind yourself just how happy a life you have given them and how funny they were, please do so. If it hurts too much to even look at a picture for the next weeks or even months, then don't- it can go either way, and either way is perfectly fine and normal. I've experienced both, depending on my bond. There will be a time when it all comes together again either way.
Please take the time to talk and to write about your feelings or - if your inclinations lie in other areas - use whatever medium helps you best to express your grief; this is the best way you can help yourself and help with processing your overload.
I would strongly recommend to contact the free Blue Cross pet bereavement phone line or make use of their email service. All the members struggling with coping with their own loss that have come back to us have done so with a positive experience and found that it helped them.
Pet loss
You can find more practical tips and contact links in our grieving guide:
Human Bereavement: Grieving, Coping and Support Links for Guinea Pig Owners and Their Children
My thoughts are with you in this very difficult time. You couldn't have done more for any of them, and that is what really counts. The rest is out of your control.