Refusing formula.

Help. I was an exclusive pumping and stopped at 10 1/2 months and have been using freezer stash ever since. But My baby boy is refusing formula. He is 1 year and 2 weeks so I’ve also tried to milk with cows whole milk. But he screams and turns his head away. And the thing is a few months ago I had to supplement as I went away for a month and my supply tanked so I didn’t produce enough. I stopped pumping then and now have 3 bags left in the freezer. What do I do?? I also know I should have mixed it but as he took not problem two months ago I didn’t see the problem and now I can’t waste my last few bags. 😢😢😢