I really think you need to see a counselor. If it is cheaper for your mom if a doctor writes a note, well, that is cool. I think that she is being supportive, but it probably needs to be preauthorized.
Yes, you need some help with your self esteem, but a lot of people do. Not everybody is as confident as they seem. And maybe you do take life seriously, but that is the kind of person that you are. I was always accused of that too when I was young.
Don't go changing things on your body. Learn to love yourself for who you are. That is the most important thing right now, you do have to love yourself before you can love somebody else the right way. It would make you less obsessive about yourself.
And at the seminar, if it sounded like you, that is because it probably is. And there is nothing being wrong with it. That is just you, and if you want to be different, you have to make some changes in the way that you are thinking. And seeing a counselor, therapist or psychiatrist can all help you. I think that a therapist would be the best place to start, so you should do that. There is nothing wrong with you, you are you and that is a very good person. You just need some guidance. And all of us need that at one time or another. So don't feel guilty about it, learn to take one day at a time. Try not to worry about things, let life happen.
Best wishes to you.
Hugs, Karen