for your boyfriend to properly claim you as a qualifying relative all these tests would have to be met
1) you lived with your boyfriend the entire year of 2019 (you say you got kicked out - if that's in 2019 then he doesn't pass this test and shouldn't have claimed you nor should he if you did not live with him at the beginning of 2019)
2) your income was low enough so the gross income test is met
3) he provided over 1/2 your support
your boyfriend claiming you is the reason you didn't get the stimulus payment. you can call the IRS 800-829-1040
First choose your language.
Then 2
Then 1
Then 3
Then 2
You should then be transferred to an agent, but there is likely to be a long wait.
you can file form 3949-A with the IRS if he falsely claimed you as a dependent.
https://www.irs.gov/pub/irs-pdf/f3949a.pdf
