I have a piece of property and it's purchase price was $550,000. I recorded it as a fixed asset within the business's journal with a credit for the Purchase Price and a debit for Loans from Shareholders.

I also have a note on the property for $350,00 which I have recorded as a decrease to the value of the property and an increase to the property loan.

Now I am trying to figure out how to record the payments made on the property. Some, of course, go to equity which would increase the property asset and some go to Interest expense.

I can't seem to get the fixed asset value to go up while the long term liability goes down. What am I doing wrong?

When you purchased the asset the journal entry should have been:
Debit the Asset(Plant, Property, and Equipment) Account C
Credit to Cash for the amount of cash paid
Credit Notes Payable for the amount of the loan on the purchase.

When you make a loan payment your journal entry should look like this:
Debit Notes Payable for the amount of principal being paid
Debit Interest Expense for the amount of interest being paid
Credit Cash for the total amount of the payment being made.

The value of the asset should stay the same, which would be the purchase price of the asset. The only time it would increase is when you are upgrading the asset

Thanks for the direction.