Zak: Listen, only you can know if you’re trans* or not, and, as distressing as it may be to be questioning your identity, it’s okay to not be sure right now. I’m not an expert, but I think there are many easier ways to get attention if you are a lonely, depressed straight girl than saying you are trans* and so it is probably more likely that you are genderqueer, transgender, or questioning your gender AND happen to be lonely and depressed than that you are only doing this for attention. But again, only you can know for sure. It sounds like you could easily be internalizing negative things your mother told you, particularly since you had been confident about your identity up until you told her.
My advice is to try to sort out the things that make you think you would want to do something like this to seek attention, and then sort out your gender identity from there. If therapy is at all an option for you, I think it would help you work on some of these things. No matter who you are, trans* or not trans*, there are people out there who will think you are awesome and want to be your friend. I don’t know how old you are, but if you’re a teenager I know that can be a very lonely and frustrating time in life and you’re not alone in feeling isolated and depressed. If there’s anyone you can reach out to, I’d recommend doing so. Being open about your feelings can help. In the meantime, let yourself explore and question your gender. Don’t do anything irreversible until you are 100% sure (or at least 99% sure), and don’t fault yourself if you find that you really aren’t trans* after all. Allow yourself permission to be whoever you really are, and give yourself time to figure out just who that actually is.
While you personally may or may not be trans*, I want to remind you (and anyone else who is reading), that wearing skinny jeans or makeup or being femme in general does not invalidate your trans* identity. There are people out there who might take your identity less seriously or try to undermine you because of those things, but that doesn’t mean that they are right and you are wrong.