Why do we do this to ourselves?

Kim • Pregnant with #1 after about a year of trying. Due end of October and very excited!
I'm 7w6d with my first pregnancy and I've felt miserable for a week.  Vomiting bile in the mornings, exhausted all the time, can't eat much other than plain pasta, very sore breasts, etc.  Then yesterday I actually felt kind of decent.  I didn't throw up immediately after waking up. I actually had a little energy and made it through the work day relatively easily.  So what did I do?  Immediately freak out and assume something MUST be horribly wrong.  Ladies! Why do we do this to ourselves?  Why is it so dang hard to just say THANK YOU for feeling even a little bit okay?  Why do we jump straight to thinking something is wrong?  I know the second trimester is supposed to get better, but I still have a month until I'm there so it seems early for that.  Why can't we just be happy to not be miserable?  Anyone else do this too or have the hormones totally taken me over?