Excel - IF AND formula not working

Love this website been using it for years, but I have come to a point where I am struggling with my formula.

What I am trying to achieve:

If disposal date = "NO" AND contractdate

If disposal date = "NO" AND contractdate>start date, =YearEnd-Contractdate+1

IF disposal date ="YES", AND ContractDate

IF disposal date ="YES", AND ContractDate>StartDate, =DisposalDate-contractDate

My actual formula is:

=IF(AND(DisposalDate="NO",ContractDateStartDate),YearEnd-ContractDate+1),IF(AND(DisposalDate="YES",ContractDateStartDate),DisposalDate-ContractDate,0))