I am the same exact way! Seriously - not too long ago one of my blood tests had elevated liver enzymes. Doc said "probably fatty liver because of your obesity". I instantly started crying because I was SURE I had some rare liver disease/cancer and I was going to die. Ugh! Anxiety and OCD make for some interesting trips to the doctor. (A month later I was retested and enzymes were "normal" - although one was at the 'higher' end of normal so you can imagine what THAT did to me).
Anyway - elevated white blood counts can definitely be caused by all kinds of simple and non-serious reasons. Most common would be infections (bacterial or viral - and you may not even know you have it) , stress, inflammation, etc. Elevated white cell counts are very common and almost always linked to something simple.
Now. DO.NOT.GOOGLE. Or Web MD! Seriously. You KNOW that's not a good road to go down! *speaks from experience*