Guess my guardian Angel is a Devil

Guardian angels will never interfere with your own freewill, and they will never draw negativity to you. You already had the desire to cut, and you were looking for a means to justify it. When the runner walked in, that was your justification. That was not a sign from your guardian angel. Your guardian angel is with you to protect you, and would never want you to harm yourself. Like attracts like. The more one thinks negative thoughts, the more negative energy is drawn to them. This isn't to say that one can't think negative thoughts at all. You can. What makes a difference is how often one thinks negatively, and how negative those thoughts are. Negative thoughts about the outcome of a school test carry a different negative energy impact than thoughts of harming yourself or others. If one thinks negatively enough, they can even draw negative entities into their life. Having a negative entity attached to you will make your life much more difficult. Try to think more positively, and remove as much negativity from your life as possible. It will make a difference.

Actually, what is happening here is called the Law of Vibration. Everything in the universe, seen or unseen, consists of pure energy that resonates on vibratory frequency. The thoughts, feelings and actions we choose also have their own particular rates of vibration. These vibrations will set up resonance with whatever possesses identical frequency. So basically, whatever vibrations you are putting out in the universe has the ability to affect the what happens around you. However, I am now putting out vibes to keep you from starving yourself or cutting yourself, because you deserve so much better than that. If you are looking for a sign to eat today, or looking for a sign to not hurt yourself, this is it. You have permission to eat. You have permission to be happy.

The circumstance of a happenstance is always perceived through the same lens as what the observer is peering through. What I mean by this is; If you are looking for something to tell you to do something, you will see that in whatever you deem a relevant source of such a message.

In the instance of the skinny legged girl, that is quite the coincidence that you would be shown that a person could have legs that skinny. It is like a "You asked, and you have been answered" happenstance.
In the instance in which you had received the slip to see the IT people, it could have been granted as an out of the entire situation that you were in that was causing your thoughts of self harm in the first place, rather than granting an opportunity to do so.
In the instance in which you suddenly stopped receiving food because you decided that you would rely on it as your source of nourishment, it could be seen as a "don't take such things for granted" lesson, or a "take better care of yourself without relying on others to do so for you" lesson. It's likely that others had begun picking up on the new vibes you were giving off, and no longer felt comfortable with sharing because of it.

What you are doing is purposely placing yourself in negative circumstances and asking for them, so of course you are going to receive them. The day you stop asking for a worse life and start asking for a better one is when it will begin to get better. And it's not just a "I want a better life now" kind of asking. It's a fully heartfelt desire to want it, and willingness to live it throughout your entire self.