Constantly Feeling Guilt Over Parents Having to Pay For Therapy

I am a senior in HS who visits a therapist once every two weeks. I constantly worry and feel guilty over the fact that my two very hardworking parents pay $250 each time for my 45 minute session. I constantly think about it and especially feel bad when I recognize that they’ve had a long day or are tired. I find it not hard to feel like it’s my fault. My mom tells me if they couldn’t afford it that she’d let me know. However, I worry about it on the daily and feel badly whenever they have another expense because I think “oh if they didn’t have to pay for my therapy, maybe they’d have more disposable income or it could go towards different expenses.”

Any advice on how to possibly cope or turn these thoughts around would be much appreciated.