Sorry for your problem.
Any history of white spot associated?
Does the movement of tongue are painful?
Any history of bleeding from it?
Ok and thanks for your all input.
Well, there are various causes of such swelling of lingual frenulum but based on the informations you have provided It certainly could be a canker sore. Another possibility is that there are two salivary ducts in that location which may be inflamed, can get blocked and lead to such swelling. Mild trauma can also lead to such swelling of lingual frenulum. I advise you to see your doctor physically, let him confirm the diagnosis and go for the treatment. In the mean time use otc tab tylenol for pain.
could - pardon the simplicity here- "sucking" too hard be considered mild trauma?
Yes, in this way lingual frenulum can get injured ( mild to severe) and in your case it can be the cause. Sucking too hard can cause more then a mild trauma as well but it is difficult to assess its degree in this forum. Tab tylenol can help you relieve such swelling and pain. But if it does not help you then you should see your doctor physically.