Hello J441! I'm gonna call you Susan, cos it's easier to say.

So I just wanted to come on and wish you all the best, from one cis girlfriend to another. (My situation's slightly different, I think, in that for a long time I thought my partner was the opposite sex; only now do I know differently).
I understand all your concerns, and I share them. I have health problems that cause me immense tiredness, yet since my girlfriend started going out full-time, I've gone everywhere with her... because I am too protective. Lately she's started going out alone sometimes, like to uni, and that makes me terrified. I sit at home trying not to panic, though luckily she understands my need for regular texts to update me when a) she reaches her destination, and b) she's about to walk home. Then I can look out the window for her and check there aren't any bad neighbours around when she's coming into view. Maybe you can ask your girlfriend to text you, too, because tbh that's what my girlfriend had always asked of *me* if I had to travel anywhere alone. Girls need to look out for each other.
Anyway, the thing is, although this tale might sound stressful, I have to say it does get easier. She's had nothing but acceptance at uni (especially from staff), and the more she goes out alone, the more I'm learning that she's okay. And I think as long as she isn't out by herself on a night-time, I'll be happy in future (and one day she'll pass *really* well, hurray!!!). She needs her independence, and I need to help her by giving her it. She's struggled enough to find herself after breaking free of her masculine shell and false macho-ness. It's the best thing for her to be out alone if the area's okay.
So... I would say that what you're feeling is natural (it's understandable to be cautious, and NEVER STOP BEING CAUTIOUS!), just... learn when it's okay NOT to be cautious. Take your foot off the peddle and trust in *her* judgement and ability to take care of herself. You can't live with such stress, and she wouldn't want you to. You both want a long, happy life together.
And on a side note, you sound amazing.

Keep fighting for your girlfriend because there'll be times she needs it, especially if she's pre-HRT. Keep her going, yet don't be afraid to ask for the same when she's having a rough time. You both need to support each other and keep talking through the rough times. Focus on the goal: one day you'll both walk out and no one will bat an eye, and she'll be the happiest she's ever been.
And so..... GOOD LUCK, both of you. I wish you all the best. xxx
P.S. I hope I didn't sound preachy or anything. I just haven't been able to get here in a few months, so it's nice to be back. And I have a bad habit of waffling when I'm happy.

P.P.S - you need to be the one to slow down your girlfriend if she's a little too eager. Get her to wait for the effects of HRT before making *any* surgical changes. It can take a year or two to see how HRT will feminise her (and some here will say longer, even!). Just... get her on HRT, then enjoy the ride together as you see changes happen. It's exciting.