Good Morning, Linda and a very merry Christmas Eve
I think that your purchase was a rather impulsive decision which is a big fight for somebody who is Bipolar. Having that coat is important to you, however, when you really look at the BIG picture in a practical sense, the money that you spent on that one item would most likely go so much farther if you put it towards things that you really truly need to preserve your future happiness. The coat would only be able to be worn at certain times whereas the place that you live, you heat, telephone, food are things that you will need to sustain you. Your parents in good faith lent you money to put towards things that you need. There was an "Everybody Loves Raymond" episode I saw in which Robert's brother and sister in law Debra lend him a good amount of money because he has no money for food or rent. Well next thing Robert is going on a trip to Las Vegas!!!

And that doesn't sit well with Raymond at all!! To Robert that trip really would make his life better as I think you feel the leopard coat will make you feel better. Nobody should tell you how to spend the money given to you, however the way in which it is spent may speak to whether somebody will be there to help you out again in the future. I am sure that your parents lent you the money to put towards something you need rather than something you want.
My daughter is Bipolar and the most difficult thing for her is to resist those impulsive thoughts and refraining herself from acting upon them. When you realize that it is part of the disorder and something that you must work on in order to not be left feeling bad perhaps that will help you be able to change and not give in to the impulsive thoughts that make you act in such a way. In the end it only leaves you feeling badly and terribly guilty so knowing that may allow you to not give in to those impusive thoughts in the future and instead allow you to conder up the strength to walk by that coat that you impulsivley want but do not need.
I don't know if you have a therapist, but perhaps with therapy you will be able to work on this part of the disorder that leaves you feeling badly. With Cognitive Behavioral therapy, a good therapist will assist you in being able to change a behavior that is bad but otherwise would be difficult for you to change yourself.
Also...is the coat perhaps something that you could have asked your parents for as a Christmas gift??? Or is it something that if you returned many gifts you do not want and took the money and have purchased the coat with??? That would have been a better way of getting the coat without leaving you with those bad feelings of guilt.
I hope that you can share with your parents how you would like to make things right between you and them again. I am sure that they know that the impulsivity is part of your disorder that often leads to trouble and your showing them that you want to change that will mean an awful lot to them. Taking the first step to do so will not only be a gift to yourself but to others who love you as well.
I see alot of posts here from you and also see how far you have come in doing all that you can do to take care of yourself and do what you must do to not allow the Bipolar to take over your life by taking your meds and realizing the things you can do to change behaviors that may not be good for you. It isn't easy and I just wanted to tell you that it is great to see that you want to do everything you can to overcome the negative parts of Bipolar. And with your attitude and strength I am confident that you will do it!!
(((HUGS))) ~ Goody