Hi ThingWithFeathers, I can imagine that must have been a really hard thing to do for you, so really well done!!!
And maybe there's no rush to tell your mum, right now?? It can be/is a massive step in itself disclosing to one person, so if you want to give yourself a little time before telling your mum.........??
But perhaps your dad could help you prepare for telling your mum, be there with you when you tell her, or/and be there for you afterwards??
But please remember whatever her (anyone's!!) reactions it's not something that makes you any less of a person, it's not something you chose, it's not your fault.
And if it hurts her then you are not the one responsible for that hurt, just like you are not responsible for the hurt they caused you.
I hope she can give you the support you need/deserve...........but if that doesn't happen, or if doesn't happen right away (if she needs time to offer you that) then you still have your dad and there are people here who can offer you support and understanding.
I know it may not make everything "better", but perhaps another step on the road towards healing.

Alison