can I sue my ex boss for letting me go before my 6 months is up that he promised me?

I worked for a self employed company~ he promised me many things and the major one was 6 months of employment after the 2 months already working for him. He let me go by changing the passwords on the emails that I worked from. Avoided my calls for a hour. tried to pay less for the my last week. has not sent me my paycheck nor answered my emails. I used my laptop to upload and download photos for him and webbed them into a vendor.