Shadow
I think you have a variety of options e.g. going for an androgynous look etc. BUT none will really resolve the underlying issue of addressing your gender identity with your mum, which I suspect you will need to do at some point.
And I agree with the others. Baggy clothes and suits etc. will for the most part disguise a female figure (along with binders if you are fairly large chested) after that it is mostly about attitude. Unfortunately it is likely you will probably be mistaken as androgynous / gay male at least initially, that is not such a bad thing if you look at it as a stepping stone / learning curve to presenting and being received as your preferred gender (Which I am assuming is male attracted to females).
Good luck. Keep us posted on how you are doing.
