Can i refile separately fur 2016 since h&r block never used my income when filed mfj on my husbands??

Why do you not go back to H and R Block to have them correct their error and file an amended 2016 return for you?  If you filed a joint return for 2016 you cannot change to separate returns after the filing deadline for a 2016 return.

If you filed a joint return in 2016, and it was incorrect, your only option is to file an amended joint return for 2016 that includes all the correct information.   You cannot change from a joint return to separate returns after the April 15 deadline. In any case, joint filing is almost always better, even if the incomes of the spouses are very different.