How serious is gallbladder pain/ problems?

Hurts. Varying degree of pain with stone or inflammation, or gangrene and peritonitis- from minimal to maximal pain. Cholecystectomy is well tolerated for most with significant symptoms.
Age/infection? Depending on the age and risk of infection, gallbladder problems can range from mild to severe. If you are having recurrent right upper sided abdominal pain, worse with foods, and have been evaluated and found to have gallbladder stones (cholelithiasis), you may be a candidate for a gallbladder removal (cholecystectomy). See your doctor for evaluation.

Related Questions

Should I go to the E.R.? Severe Gallbladder pain, diagnosed with stones and sludge-balls. Awaiting surgery date.

RUQ Pain. The presence of gallstones and/or sludge within the gallbladder does not necessarily mean you have acute cholycystitis. However, if you are having severe abdominal pain, especially within the right upper quadrant, and you have ANY fever, I would consider evaluation by a doctor, as soon as possible.
My God, OfAllThe Gall. If you are hurting so much the pain medication you are taking isn't helping (assuming you're taking it as directed) &/or you are vomiting everything or most things you are eating or drinking &/or you have a fever &/or you are urinating less &/or your urine is getting darker & darker &/or your eyes are getting yellow &/or a large black crow flies in and impales itself in your stomach, go to the ER.

Is gallbladder pain always severe? I am having very mild pain, maybe a 2 on scale of 1-10 just under my right ribs. Comes and go, have had it for years

Not necessarily. No progression of pain or other related symptoms or signs does not necessarily needs to be worked up.
Gallbladder. If you have very mild pain, that should not stop you seeing your doctor to understand all of your concerns. You are still young enough to be a father.