I turn 18 in 3 months. Im constantly very dysphoric about my chest sometimes I really want to use grandmas saw.. I hate it. I cant stand how I look
It can take time, sadly. Months for some, years for others. In some part, it depends on therapists and letters, but it think it mostly depends on money and - if you're in the US, at least - insurance. I don't have that here in England, I have NHS, so I don't know exactly how long you may have to wait if you're in the US. It's different for everyone. The best thing you can maybe do is try to make yourself feel a little more comfortable, like with a binder, and focus on things that make you happy, like a hobby or being with friends. While you go through the steps you want to take to transition. Having a goal, knowing in the back of my mind that one day I will have surgery, it can really help me. Maybe it'll help you.
Realistically, most people wait for financial reasons. What I recommend is start T, get to the level of fitness and height/weight you plan on staying at, than get it done. I know chest dysphoria is very powerful, I had issues and so did a friend of mine.
There are some surgeons that require that you are on T for a certain amount of time before you get top surgery. This is because T changes how the fat in your body is distributed. Also, you have to have a letter from a therapist, and that takes some time to get as well.
Binding. I'm currently waiting to buy a new one from GC2b. Their reviews are constantly good compared to others, that I've seen, and they're not that expensive ($33-$35, which is about £21-£23). For now, I have a binder from a UK based charity called MORF. They ship internationally and you only pay shipping (I think it's £7 (about $11) to the US). If you google free and cheap binders, you'll find other sites like that that are based in the US. Hopefully you'll find one that is right for you, but I would invest in one from a place like GC2b/Underworks. They may cost a little more, but you're more likely to get one that fits you right and will make you feel comfortable.