I work at a grocery store and they make me use the male restroom. An customers that do not know me walk into the bathroom and it causing problems. I don't look like a guy and get confronted almost daily and one day it almost got physical when a customer tried to grab me and take me out of the bathroom. The company doesn't want me to use the female restroom till i completely transition voice, and srs. Plus they fear customers that already know me will complain that i am in the female restroom. I kinda feel trap and kinda starting to fear something bad gonna happen if this keep happening.

Rosey that sounds harsh, wrong and dangerous for you.  So sorry girl!  Depending on where you live and your employer you can seek assistance from a union rep if you are in one.  Personnel or HR can assist if they exist.  Non profit groups like the ACLU can help.  Are there any LGBTQ centers in your area?  Currently the federal government in the US might have your back.  Check on line for Transgender Equality groups.  Transition to being legally female does not depend on your voice or genitals in many states. And ultimately let friends know and consider a better place to work.

Find out what the law is where you are.  There are some places where the law says your employer is right, and some places where the law says you are right.  If the law is on your side, let the employer know it, and tell them that the customers are complaining about your being in the men's washroom.

This is horrible and seems like you are trapped indeed... it would make much more sense to use the ladies room, even if it would cause problems, they would be at least lesser than what they are as of now, in my opinion... as the other ladies said, please find our what the law says in your state, find a LGBT centre and try to get legal counsel/lawyer support if needed... know your rights and be ready to fight the right way if you must.
Really what I think you should do is find another job... it seems the employer is not sensible at all at your situation, and you should not have to deal with a situation like this... no one should.

Depending on where you live,  can you update your drivers license to the female gender marker,  you must have sone some sort of legal protection. If your being harassed in the mens room and they are forcing into it, you should have some sort of legal protection .

Your personal safety needs to be their number one concern. It sounds as if you would prefer to start using the ladies room. I say that you should use the ladies room, and "how far you have transitioned should be a mute point". I assert that (A) The ladies rooms have doors... you are exercising a right to privacy. (B). Nobody should be peering over said doors... that's pretty much illegal in most parts of the world. (C) Who the hell starts up a conversation in the bathroom!?!?, so voice is a "non-issue". What are their concerns that we haven't just addressed?