so for once and all:
I'm afraid of injecting, I don't know how to do it. What should I do.
Injecting is something everybody can do. Basically you pierce the skin with the needle, when it gets a little tougher, you've hit muscle. push through it. Now pull back on the plunger. If no blood enters the syringe, inject. If blood enters the syringe, pull the needle back slightly and then inject. Always make sure the muscle you inject into is relaxed. if you inject into the glute, you NEED to sit down to make the muscle relax if you inject yourself but stand up when someone else injects it. With the quad, make sure the knee is bent.
You can learn how to inject here, including all types of spot injections :
http://www.spotinjections.com/