For About A Year Now, I've Had Random Raised Bumps

for about a year now, I've had random raised bumps on the back on my neck that come and go. Sometimes they have clear liquid that comes out when I scratch them. Most times, nothing at all. If I mess with them, or pick at them they get very irritated and seem to spread. Sometimes, they dont go away for a long period of time. Like a month. It's starting to really freak me out.