How do I get help?

Hi everyone,
I need some advice. I think I have depression, and I'm pretty sure I have social anxiety. I say this because they are things that you 'just know', but I'd really like to get diagnosed and receive treatment for them. I first had symptoms of depresion when I was 16, and it took me a long time to open up to my mum about it. When I finally did, she reacted badly. Really badly. So much so, that I can't bear to think about it because it makes me cry each time. That was a couple of years ago, since then I've tried to put on a 'happy face' so she'll be more accepting of me. But the problems are still there, and I hate it. I really want to see someone about it, but there's no way I could convince her to allow me to get help. She also criticises me for my social anxiety (which I find much more difficult to hide than depression) and believes me to be an 'embarrassment' for not wanting to meet up with family members. And I know it sounds silly, but I can't ring up and make an appointment on my own - my social anxiety makes me panic, stutter, etc. and so I know I'll just get too embarrassed to carry on. Also, I know I will find it incredibly hard to speak to someone about it, yet I don't want to feel depressed and socially anxious anymore, so I just want to have the opportunity to at least try to get help. Thank you.