The "geep" born in Ireland was a witnessed mating between a sheep and a wild 'goat' which from a distance may very well have actually been a horned native breed sheep.
It may be worth getting the vet to do a scan just in case.
Goats can also have false pregnancy, so a scan would pick that up too.
Goat sheep hybrids are possible, but the foetus is not usually viable so leads to abortion or a stillborn baby.
Mastitis can be difficult to cure, and sometimes requires multiple treatments intramammary, and even systemic injections, and can reasonably frequently end up with permanent scarring. I would talk to your vet about it as they should be able to advise you best.