Do you think you could go to school? I have no idea how the U.K. works with education, but if its anything like the U.S.A., could you apply for grants and loans? I am going to school through an online program, which is very convenient for me due to having a host of physical illnesses/diseases. I am working on my certificate in administration so I can work soon and work towards independence. I plan to save my money for a car, learn to drive it through driver's ed (cause my dad won't teach me for reasons I cannot fathom), save up money for a down-payment or security deposit towards my own housing, move the hell out my dad's house, go back to school once again on a program called fast-track to earn my B.A. and master's in psychology.
You gotta come up with some future goals. Even when things seem hopeless currently. You need to do some researching. I would ask for maybe some resources or something from some members here. Like FTMax and Laura 7 are very good about this and more. You can't expect life to magically work in your favor. Most of us have to earn the things we want, even if we are entitled to it, such as your human right to be called the name you want and the pronouns you want.
You ain't gonna like what I am about to tell you, but until then, if you have no job and no car, you gonna have to just put up with it, man. But while dealing with this you can go on your computer or phone or whatever you use to communicate with us here at Susan's and search for as many resources as you can in regards to the help you desire for getting what you need/want in life.
I know what you must be experiencing with your parents and stuff. They sound kinda passive about your situation. My dad is similar but I think your parents are at least more attentive to it than mine, especially my dad. He doesn't even mention it at all. Your parents at least talk about when they would feel comfortable about having you come out to your brothers. My dad does not ever talk about this and legitimately treats me as female as he did when I was conceived.
Do you have a gender therapist? If so, I advise to you that maybe you should offer to have them accompany you to your therapist so they can explain and educate them about what it means to be transgender. Its sounds to me, and I could be wrong, that they are indeed in the grieving process of your seemingly new identity. They are trying to understand but are really struggling with it, especially since they themselves are probably not trans. We don't understand what being cis is like so how can you expect them to comprehend your pain?
Its hard, man, but try putting yourself in their shoes for a change just to get a glimpse of what they are struggling with.
-Phoenix