Sorry I can't be of more help. In fact I opened mainly because I didn't know what a fenulum is, how is it this word is in your vocabulary? Are you a medical person? May not be relevant, but my point may have something to do with the lack of responses.
From what you describe I can only say, see a doctor.
You made a very good point, thank u! Fenulum actually wasn't a part of my vocabulary until yesterday, I googled the tissue that attached to the tounge since that's where the lump was located. I got my son into his Dr and it turned out to be a stopped up saliva gland but it relieved itself thankfully!! I the pressure became enough that the lump busted and the saliva inside came out. He was lucky that it took care of itself because they don't always do that and it was very painful. When it did finally bust the pain immediately began to subside. Thanks for ur response ill remember the point u made next time I post a question and I'm not in the medical field I just thought it would be better to ask about it using the medical term but I think u were right. Thanks again!!!