I can understand, I'm sure I'll have a hard time convincing my mom, when most of my interests are 'male', and I spent all my childhood pretending to hate girls and all girly stuff, and now, if I came out to her, I'm sure she'd be surprised and shocked. I wasn't visibly 'unhappy' either when, I always kept my unhappiness and depression hidden, and only in the past few years have I let her in on the fact that I'm pretty unhappy with life; but I never really told her why I'm unhappy though.
Sometimes, the time isn't right for taking a big decision like transitioning, I'd say you did the right thing by waiting to finish university, now you have one less thing to worry about, and probably feel a lot more secure.
It's always nice to have a friend who you can confide all secrets too, makes life a lot easier.