BIG HUGS
I am so sorry that it is all coming together for you in perfect storm. It sounded very much like Ted was already on borrowed time for me.
Could you perhaps tell your kids that Ted is very unwell and is staying on at the vets/with a vet nurse overnight (where he then dies during the night) if you'd rather not spoil the birthday celebration itself with the bad news?
Here are our tips for looking after bereaved piggies in the immediate and medium term.
The guide also contains links to good standard rescues in several countries, most of which offer boar dating under expert supervision at the rescue - this would allow Elvis to choose who he gets on with and you are assured that you come home with a fully quarantined/vet treated, properly sexed piggy only after acceptance has happened. You also have the rescue as a back-up if the relationship is running into trouble at any point of the adopted piggy's life.
Looking After A Bereaved Guinea Pig