if your spouse will not agree to a joint return, that leaves you with the following
if you did not live apart for the last 6 months of 2021 you can only file as married filing separately
if you did, then did you pay more than 1/2 the cost of keeping up a home for yourself and your child who lived with you for more than 6 months in 2021. if not then you can only file as married filing separately, if you do meet these tests you can file as head of household.
if married filing separately both must use either itemized deductions or the standard deduction. if different expect a notice from the iRS.