Your best bet is to leave your problems at the log-in screen and not speak of them. I had this problem for a bit so I turned to talking to people whom I can actually speak of this to.
Work on getting a grip on what you say before you say it, don't say things and then say that something isn't important enough to be looked at (Sounds a lot like my doctor), and overall just try to have a better attitude.
Heres a tip of advice: If you ever feel down/hurt/whatever just force yourself to laugh. Once the fake laugh starts you'll begin to laugh for real and your mood will lift.
I have nothing against you, nothing at all. I'm not one to hold a grudge.