What happens if I can’t make my Trustee payments in Chapter 13?

In a worst case scenario, your case can be dismissed, and you lose the benefits of bankruptcy. This does not mean that your property will be forfeited. Your relationship to your creditors simply returns to being governed by state law. You owe debts to the extent that they have not been paid, and creditors go back to having state law “remedies” such as repossession or garnishment.
If your inability to pay is temporary, a request can be made to the court for a limited suspension of the obligation to pay, and, as noted above, sometimes your payments can be lowered. Once again, the amount of debt being paid, and the time you have left on your plan may restrict what you can do in this regard.