The parents do NOT absolutely qualify to claim you as a dependent. You state that you provided more than half your own support, just not with earned income. That would disqualify your parents from being able to claim you.
However, distributions from a 529 plan, where you are the beneficiary and your parent is the owner is usually considered support provided by the parent and not by you. Reference: https://www.savingforcollege.com/articles/the-impact-of-529-plans-on-claiming-a-dependent
Trust income, where you are the beneficiary of the trust, is considered your money. But, mere receipt of investment or trust money is not support . You must actually spend the money on support. If you put the money back into savings or investment, you haven't spent it on support. and it doesn't count for the dependent support test.
