Hey,
My name is Paul, and I understand what you are going through. Your ups and downs throughout your life sounds a lot like bipolar disorder. When it comes to seeing a doctor, call them everyday and ask if they have any cancellations, and you really need to see the doctor asap. Sometimes this helps get you in faster. You should get it out of your head that you are not worthy of a good life. Self-esteem plays a very important role in your well-being. Remember, the only things in life we really control is our actions and reactions.