If you really want to change you can go to the gym or workout at home there are plenty of videos online
If you think your teeth are bad, go to the dentist and see what they say. Bad acne = go to the doctor.
Dark circles could be genetic, from lack of sleep or dehydration. A colour correcting concealer can also help. (If you have blue tints use an orange concealer)
When you feel bad about yourself you usually look for more reasons to hate yourself. Your height shouldnt even bother you because its not even important what the "average" is. Im like 5'1/2, why do you want to be average?
Relax, think about why you have discolouration, again, maybe you can talk to your doctor about it?
Im sorry that you were bullied. Many of us go through bullying and its not a pleasant experience at all. I dont really have any advice here because I just endured mine until they gave up.
Your family shouldnt be making fun of you, just remember that beauty is subjective.
Im sure you're not doing well because you're upset. (I know I was) Self improvement starts somewhere, and you can start to feel better about yourself if you make an effort trust me. Also, jobs are hard to get, but don't give up searching!
Please do not determine your worth through other peoples opinions. There really is more to life than that, you just haven't experienced it yet.
Please do not ever attempt suicide, I know tons of people probably would say this but it really isn't the way to go, you wouldn't feel any better about yourself. The past is the past, you can use it to improve and develop into a better person.
Im sure you are tired, but please do not give up. Only you can change your mindset and situation. I would start by making small efforts everyday or doing some self care. (Take a bath/shower, go on a walk, treat yourself) After this you can take baby steps towards anything you have a problem with. Don't try to look for more reasons to hate yourself. You are only 17.