Sweetie, you need to see your doctor to start with, it's pretty obvious you have anorexic tendencies, which not only affects you mentally but physically can really harm your, especially in your teenage years.
I've been in your shoes, with emotion rejection and being teased for being overweight.
Eating Disorders gives us some control in life, especially after feeling abandoned from your parents divorce, your grandmother moving and then passing away. You've had to handle a lot in a short period of time.
See if your family doctor can set up with with a psychiatrist, and get you on some meds to start with, and some good talk therapy. Depression is pretty normal, especially with what you have gone through, talking with someone is going to really help you. Believe me it will.
When you posted about vacations and material objects, it's because it will distract you for even a little while. Happiness isn't a thing, or a place, but something that can't be measured. You'll figure that out,. You aren't alone with feeling that, I'm darned sure most people have that at one time or another.
I agree with leftcoastchick, I would def go to a dr. and poss. try an anti-depressant. I have never had a eating disorder but I have had and still do have everyday battles that I struggle with. Therapy didn't help me but talking to others in my family did. I take lexapro 10mg and its helping but, im thinking of trying abilify with it. Im not gonna tell you I know how you feel because I don't I just know that trying some different outlets for help will def. help you. It will certainly not make things worse. Also it sounds like you have a great mom so let her in as much as you can. I have a 5 year old and I would die for him like most parents would do for there child. Im sure that letting her in and trying to help you might make things easier for you....
I don't know like I said.... I hate when people tell me its gonna be alright or they know how I feel and it makes me wanna scream... So even if just talking on her helps.
Im only 23 so if you ever just wanna talk to someone who might beable to relate better to you let me know.