if you get marketplace insurance you should have gotten form 1095-A which is needed to complete form 8962. failure to enter this info will result in rejection.
the out of pocket may not be correct because of any 8962 adjustments. you could get an additional PTC which would reduce the amount deductible or if you got too much PTC you might owe (there are exceptions to repayment) but any repayment would add to the deductible amount.
in any case, Turbotax should be carrying you correct out-of-pocket to medical expenses.
also, you have to have enough in medical expenses to exceed 7.5% of AGI to get a medical expense deduction, and even if there is your itemized deductions would have to exceed your standard deduction to get any benefit.