big bumps or knots protruding from trunk
I think someone told me that bugs bore their way into the tree and that I should cut these bumps off and burn them and apply some kind of ointment to the wounds to prevent the bugs from returning. Do you know what kind of ointment that is?
Making a determination as to the exact condition your tree is suffering from is the most important.
Whether it is a canker, gall or another issue, I would not recommend cutting the bumps off. This will invite insects, fungus and cause more issues that your stressed tree is all ready suffering.
Galls and burls on a tree can look awful and generally are not an issue.
You may want to call in a professional arborist to inspect your tree.