For 3 days I've had very thick yellow goo when I cough. Chest congestion and at night way way too much spit. Never had this before no other symptoms.

See your doctor. It's always a tough call whether or not someone needs antibiotics based on symptoms alone. Even though the mucous is yellow, it doesn't necessarily mean there's a bacterial infection. A doctor needs to take a look at your vitals, sinuses, listen to your lungs, possibly check your oxygenation and /or a chest x ray to determine the best treatment for you.
NEED A CHECK UP. You need to see your doctor to have a check up.Yellow goo is of no concern.But chest congestion and too much spit needs to be evaluated.You may have acute bronchitis or just a viral upper respiratory infection.In meanwhile drink plenty of fluids and take some over the counter cough medicine till you see your doctor.
URI. Symptoms may suggest upper respiratory infection which is more commonly viral but could be bacterial. Decongestants, cough syrup and fluids will help.