Since you've cleaned out the burner area and the flame is now strong and blue, I think you may have solved the problem. As for the freezer being ok, the frig cools the freezer first, then the fridge. So, you may just have to give it some more time.
Another factor may be the temperature outside. If it is over 80 or 90 degrees, your frig is going to have some difficulty keeping the frig at the correct temperature. A solution would be to install a fan to the outside lower vent to blow air into the back compartment and help the natural chimney effect that would normally cause the warm air to escape and cooler air enter.