I'm kind of in the same boat you are in Ashley. And here's what has really helped me out so far.
Well first off this forum is wonderful and I've found so much support. And being able to write it down really helps me out.
As others have said go see a therapist. I haven't gone to one yet but I'm fixing that in a few hours. This is a good site to find one
https://therapists.psychologytoday.com/rms/?tr=Hdr_BrandIt sounds like you already have the clothes thing covered if you have girlfriends to shop with. So that is going to be a goldmine of information for you. Biggest thing is making sure everything matches when you wear it. Also go easy on the makeup. Try not to hit the princess phase with way too much.
Get your walk pattern and mannerisms down. One of the biggest things for passing is actually acting like the gender. Turn your hands 45 degrees so your forearms face forward, walk with your hips, let your body flow as you walk and also walk in a straight line. Keep your legs closer together when standing. Make sure to cross your legs this is mandatory when wearing a skirt. Try not to look like you are leaning forward while walking. Males usually have their shoulders hunched forward start keep yours shoulders hunched back. This will help make you look less muscular. The other night at work I'm pretty sure I saw a couple cross dressers that were trying to pass. But they were not doing that great of the job. They had on high heels that made them taller then me and I'm 6'3 and the walking pattern was really stiff and just did not look right. I don't know I might have been wrong.
Make sure you are polite and yielding towards people that come towards you. Just don't be meek be polite. And when you smile use your lips and maybe show just a little teeth. Males show a lot more teeth when smiling.
Also one big thing don't keep looking at the ground or avoid looking at people. You'll end up getting more looks from people since they'll since that you are being self conscious. You'll just end up drawing attention to yourself and might end up getting clocked. Just have confidence in yourself and if you do get looked at weird shake it off.
One good thing to do is maybe go to a mall or cafe and just relax and observe how gals act. Just make sure you don't look obvious.
As for your job being physical work I can understand that.
Hope this helps you out
Raven