My week, so far

As I left for work this morning gf claimed that I look unhappy and that she wants me to cheer up because she'll start worrying about me if I don't cheer up any time soon.
I told her that I didn't sleep well and that that's probably the reason, nothing to worry about.

On my way to work I started thinking and concluded that my week so far was pretty bad and maybe that's why I'm not all chipper.

Ironically, Monday was a good day. I left work on time and got myself a snake board.
Tuesday, I forgot my little sisters birthday. Well, I didn't forget it, really. In the morning I thought of it but I don't like texting in general and much less if it's a happy birthday text, it's not personal enough. So I thought of calling her later when she leaves school. Naturally, I got caught up in stuff I needed to write for Uni and completely forgot to call. So at around 10 or so she sent me a text to ask if I had forgotten. I called her back and apologized and she wasn't mad at all, but I still felt very bad about it. She turned 18.
Wednesday, I had to wait 45 (!!!) minutes for the bus to come. Luckily, I was only 5 minutes late for work but even that is too much for a punctual person like me. Also, the bus schedule was fucked up for the last three weeks already so I called and asked and even though the person on the phone was a real sweety it didn't lift my mood. I thought to myself that at least I'd be able to leave work on time. Ha! I didn't. I stayed an hour longer than I wanted to and came home beat.
I didn't sleep well last night, god knows why and so today - although it's a sunny and so far ok day - kind of pisses me off too.

I HATE it when I am that way. I am a fairly balanced person usually, but when at some point I somehow fall out of balance it takes me forever to get back...Does anyone have a suggestion on how to stop this mood of mine?