To be frank, its a band-aid. You just need to rip it off.
In other words... once the first dose is in, you will feel differently and because there at that point is in fact no point at all in worrying whatsoever about it anymore. Its the 'unknown' that you are stressing over right now, trust me I know. That's all it is and I'd think it abnormal if you WEREN'T going through it like the rest of us did.
The 'Androgen euphoria' does wonders to clear up the lingering bit of anxiety as well.
Things you didn't understand before become crystal clear and it's awesome. Its not all roses, but the benefits far outweigh the minor annoyances (e.g. feeling like you've been steamrolled over on from the muscles and ligaments bulking up and stretching out etc).
Meantime, you just need to find some distractions. Video games, books, movies. Whatever. Find something to do to take your mind off of it. It'll drive you nuts thinking about it with nothing to do.
That all stated, I will caution you that if you're not going to do the 'low-dose' option to start with on the T, changes happen very quickly. My Endo decided to just start me off on what we'll term 'comparable to normal male level' T straight off and my voice wasn't the same as early as the next morning. So just something to think about. Some like the changes to happen as quick as possible (that's me). Some prefer them slowly, 'low-dosers'.
So this is a very big decision and I'd personally think you barking mad NOT to have some anxieties about it. Nothing to be ashamed of. A bit of fear is not only normal, its healthy. Its there for a reason.