My partner usually handles our rent

we rent from his mom, and i use all of my disability to pay for my half (700 or so) its all my money because I  cant work

this month I wanted to give the rent to his mom myself and he got very upset with me.  I got suspicious but have him the money to avoid being yelled at or fighting

I had a bad feeling so today I called his mom and asked if she got the money (somthing he told me NEVER to do)

She told me she had been paying our rent in full for 2 months and received nothing.

I also looked at my partners bank statement since he left himself logged on to the computer 

he cashed his paycheck yesterday told me we only got 200 this month, he lied.  we had more like 500

&amp;#x200B;

I dont know what to do, he knows im not well ans this is not okay, i dont know how long he being lying to me like this but i feel like im going crazy.