quad injection

I'm in week 5 of 150mg test prop EoD. The past 5 weeks I've been alternating quads and everything went smooth. However, I started to develop some scar tissue and I'm finding it harder to pin quads. For some reason, as soon as I stick the needle in either quad, I almost instantly get light headed...

Today imma do my first quad pin. I was lookning at a video of how to do it and I have a question. In the video the guy shows that in ur quad there are 3 main muscles, down the middle, one on inner leg and one on outer leg. Now he shows that u either pin the inner or outter muscle. So my...