Eating disorder?

I am 25 year old guy, I am already slim but I want to be slimmer and i cant get it out of my head, i can go for 6-7 days without food, what should i do?

I wish there was better solution, but you need professional or sponsored help. I mean not check yourself into a rehab, but get a counselor and express yourself first. Or join a group dedicated to eating disorders because it sheds light to the problem. Admitting you have an eating disorder shows your not too far into it. But if those don't help, you may need to check yourself into a rehab if it gets worse.

See a psychologist and see a doctor. Sadly, I think you have anorexia. If you continue on with this behavior you won't be here.
You suffer from anorexia nervosa. See a shrink.
It sounds like you do have an eating disorder, and it also sounds like you know it. Go to a Dr. before you completely go into denial. It's best to get treatment as soon as you can.
First:EAT!
Then Seek medical assistance immediatly.

Also, tell a family member or a close friend.
what do you think being slimmer will do for you? If you let food or not eating control you this will become an addictive illness and like heroine your personality will be destroyed and all that will remain will be the illness. Your brain function will diminuish and you will never be free of the illness. Talk to your doctor and get counselling now. I'm 40 and have battled anorexia and bulimia since I was 16. It has been hell and destroyed many friendships and relationships. You can learn strategies to deal with these thoughts and feelings. Emotional Freedom Training EFT is really good. But you need to find out why you are punishing yourself. This is self-harm and will get worse if you don't get back the control now. You are actually a health and safety hazard if you go so long without food. also when you do eat your body will bloat. Look at how the stomachs of children bloat during famine. Those kids don't have a choice about eating you do.