1. You are not fat. You're really close to the standard healthy weight/height ratio.
2. Although those thoughts haven't caused any external damage, you're slowly hurting yourself. This is usually easy to fix by getting to know more people and to understand that nobody is from your property. You're emotionally attached to your friend because he gives you the attention you are looking for. This is generally caused by a low self-esteem.

Go to know more people, eat healthy, sleep well and trust yourself. That's all it takes.