Sorry to hear about your boar :(
How old is she Sucks?
They do prefer company of their own. However be prepared that if you get another then you will need to do all this again when your old girl passes.
It may be possible, as you have a sow, to get another two. Sows can live in bigger groups if that's what you wish, less chance of falling out that there is with boars .
Is there a guinea rescue near you. They will find your girl a friend.
Another option, if they don't get on all together is to keep them side by side. I am having to do this due to my boys refusing to get along in the same cage. they are happy that they can see and smell each other through the bars.
Its not ideal, but its a very close second :)
As for her being bullied by the boar, he was obviously the dominant one. They will have they pecking order. It might not look nice to us but its completely normal :)