Bouncer is correct, however your head rush could just be from panicing, or anxiety from the inject. when I am injecting I make sure, I am breathing deeply and slowly, controlling my breathing. I can see where one could panic, and start getting light headed. I injected 2 cc's for the first time, and I got somewhat light headed, because the needle was in there much longer than I ususally have it. Inject slowly, stop rest, and start back again. Until you have completey injected your gear. Just try and relax.
Normally when you inject into a vein, you will know. You get light headed and feel like you are going to faint.
As long as you asperate, and try to keep the pin in one position. I normally when doing say a thigh inject, shove the intire pin into my skin, that way when I asperate, if I see no blood, then I can't go any deeper.
If you asperate and see blood, pull the pin out, reinsert another pin and try again in a different spot. I have seen and heard of guys going thru a vein, and never got blood until they pulled the needle out, and blood went everywhere. I have had something similar happen like this to me, but never to the extreme some guys report.
Happy sticking. !!!!
BTW bouncer I am here for New years just like you.. LOL boy we must be some boring mofo's..