@chelder93 - from what little information your provided, sounds like your boyfriend's PARENTS may be the ones who can claim you,
1) you do not live with your mother so that disqualifies you to be her dependent.
2) does your boyfriend pay your fair share of rent /mortgage, utilities, food, insurance, etc on your behalf? sounds like "no" since you state your Mom is paying for everything (does 'everything' include the rent to boyfriend's parents?) .. But if his parents are not charging you for rent, utilities, food, etc.
how much is your income? if over $4200, no one can claim you!
please read closely what @xmasbaby0 provided as the rules for a "qualifying relative"