Talking to a doctor about depression

So I'm 22 and I've been dealing with depression and anxiety since I was about seven years old after my parents broke up. In getting older it's been more difficult to pinpoint what exactly triggers me. It can be anything and nothing at all. I've accepted that these are emotions that I will likely deal with for the rest of my life. Although lately it's been taking a real toll on me and it's becoming too big of problem for me to deal with on my own. I know I need help but I just don't know how to bring this up to my doctor especially without bursting into tears and having a full on anxiety attack. Personal experience and any kind of advice would be much appreciated!