I have a irritation under my tongue that comes and goes. no visible sore or cut but maybe a swollen glan? any ideas on what it is and how i got it?

Needs to be seen: These type of situations need to be seen when you actually have the sore present. This is the only way to determine what it actually is and how best to prevent or treat it ( if possible). Merely giving you a list of possibilities will not serve you in any way.

Possibilities: Could be anything from a partially blocked minor salivary gland, a partially calcified major saliva gland duct, a draining abscess, a neoplasm, or so many other possibilities. Next time area is irritated immediately see your Dentist for appropriate diagnosis...it has to be seen/palpated/imaged/tested/etc to be diagnosed, from which flows the correct treatment options