Brusch problems

My brush does not work properly. It flows too much and it can not be set to the right size. It is either small or huge. Sometimes when I use a brush or clone stamp, it stretches in all directions. Sometimes it helps to restart PS but not always. I've had it for so long now. And it does not get better despite your updates. Now I'm starting to get tired. I pay for a service I do not get.
I really need help with this.

//Cindy Grundsten