The only happy time of my day is when my beautiful coworker pats my should as she walks by.
Why does that make you so happy?
Because she's strong and tender like a soft fluffy cloud.
Although it's good that you are able to find some happiness in your day, relying on someone else to make you feel happy is not good. You need to be able to find happiness in yourself too or else you will almost never feel good. Try to find a hobby you enjoy so you have something that makes you feel good on your own.
But I want to be happy when she pats my shoulder. That feeling is amazing.
I get that you like when she acknowledges you, but that should not be your only joy in the day.  You should make your own happiness and not rely on just one person to bring you joy.