I have a pimple like sore with clear liquid coming out when I squeeze it on the backside of my hairline it's extremely red due to pressure and squeezing it and is very painful it seems to be spreading

Very common. A big pimple or cyst can be filled with water, oil, or blood, or all 3. Squeezing is never a good idea unless you keep it CLEAN. Wash with soap and water, rinse well, pat dry with a clean paper towel, and apply a cream containing antibacterials, easily bought in a drug store, and a band aid.

If the surrounding skin gets red and spreads, see a doctor tomorrow, because if bacteria got under the skin, you will need antibiotics.