Change Creative Cloud Pro plan

I signed up for a free trial for the Creative Cloud Pro plan (annual, paid monthly). I forgot to cancel my free trial so I just got charged $67.99. Now I want to change my plan into something cheaper but I couldn’t find any option for that, I can only cancel the plan but that will cost >$300. Please help me out. I really cannot afford this, I need a cheaper plan or change into a cancellable plan. Thank you