Just hang on in there. It is a very encouraging sign that your companion is still eating a little; this means that although she is upset and grieving, she is not acutely pining and will hopefully come through it. If you have any suspicions of illness, please have her vet checked promptly and please keep a closer eye on her weight in the coming days. There is likely to be a bit of a dip but it should not surpass 50g/2 oz.
Please don't worry about drinking; she'll do that on her own when she is feeling really thirsty. The more watery veg you feed, the less she will drink.
Use our piggy whispering tips to reassure her that she is a beloved member of your group; talking her language and giving her a feeling that she belongs and is loved and cherished can help her enormously right now. Respect that she needs to grieve herself. Being withdrawn for several days is a normal reaction.
Keep an eye open over the next weeks but try and see whether you can date your girl before you bring any newbies in. Otherwise I would keep any potential companion in a divided pen so the piggies can get to know each other and the newbie can settle down for at least a night or a few days (babies are desperate for company, but allow your teddy girl to get her bearings).
You can never tell who they piggy will be happy with. After coming closer to 100 bonding attempts my experience echoes that of many rescue people offering piggy dating and doing in-rescue pairing up with their own piggies. All you can do is try and have a plan B ready if i doesn't work out.
Bonding and Interaction: Illustrated social behaviours and bonding dynamics
All the best! I find losing younger piggies hardest to cope with, but trying to find a constructive way of dealing with the guilt issue does help. It is not about the falling, it is all about the getting up. Give yourself time to grieve. Regain your piggy by remembering all the good times, the love and care you have given. We can never control how long for and what from our piggies die, but if you have given your piggies many happy todays, then you have not failed because that is how they measure their life by.