I get these little clear blisters/bubbles under my tongue all the time and they hurt... I'm kind of scared for what they could be...

Don't worry. Minor salivary glands that get blocked are clear little bumps(clear saliva in a tiny skin sack) that heal once they pop.
Herpes simplex virus. Cold sores, sometimes called fever blisters are groups of small blisters on the lip and around the mouth, but can also appear as clusters in other areas inside mouth ( roof mouth, gum..). The blisters may break open, leak a clear fluid, and then scab over after a few days. They usually heal in several days to 2 weeks. Just to confirm and be sure see a dentist next time they appear.