Wow you do have alot going on and it seems your guilt over what you did and not being up front and honest and open with your parents is eating you up. The thing is your parents love you plain and simple and they just want what is best for their son. And like your dad is trying to tell you we will get through this together no matter how hard it gets, he is gonna be there to support you and that is great that your family loves you that much.
Now you have to start trying to love yourself and not be so critical of yourself. I know this is hard but it is something to work on. Also forgive your self. They have forgive you so move on and just be honest with them. Tell them you can't go to the psy. doctor because you owe money. I realize you maybe thinking your saving them by not saying anything but this is not what they would want. They would want to know and help you to get the help you need. And if it means being on ADHD medicine for awhile that is alright too. With any medicine there can be side effects but there also can be good results with it..And it does not mean you will be on it forever you may just have to take it awhile to you can get things straightened out and feel better.

Are you OCD by any chance? I ask this because I am I am actually pure O and obcessing is one of my worse enemies. As I have gotten older I am much better about it and do not fear the things I used to like what if I die, what if I get sick ,the what if's used to drive me crazy. One day a very wish doctor said to me when I was about 30 well dear we are all gonna die someday but what if you live to be 100, what if you keep stressing over the what if's and never live your life. Get out and take it day by day or moment by moment and live in that moment not in the what if's. He was so right and that helped me more than anything.

So work on forgiving yourself and getting some of the negativaity out of your life. Your worth alot more than money. So keep trying life is a gift that we have to learn to make the best of and I wish you nothing but the best. Many Blessings!