good luck with your mum. However open minded and supportive your family are, they will probably have difficult feelings to deal with too. They may need a little time to say goodbye to the old you and to get to know the new one.
And if anyone in your small town can't accept it immediately remember you will soon be off in a new city with people who won't care who you are attracted to, they'll just want to get to know the person you are.
hope it goes well.