well, the only way out of ur contract is to prove that ur current employer violated his obligations with u, in salary, benefits, any other obligations, or u will have to stay with him or leave Qatar, and then he might  prohibit u for 2 years i think from entry rights to qatar.

Note : if u have been working for long with him, this is another case, but u should consult a qatari lawyer,

hope u the best,,,