i think your problem is your dad, hes forcing you to head to the real world too much in his way and his way is totally unnatural for an enfp. you should really try to get your dad understand what he is doing you and that his way of doing stuff is not for you and its only making you miserable.
I have noticed that if enfp is forced to do anything they will go into defensive mode where they start resisting everything that the person is forcing them to do even something they only suggest, even if they would enjoy it if they would have made the same decision by themselves. it seems that your dad forcing you to live your life in certain way is making you to go in this kind mode. But since he is making you(not just trying to make you) go his way(atleast in some degree) you do as he says, but you cant enjoy it(your life).
you should really start doing things your way, but you shouldnt go from one extreme to another, finding the balance is the key to everything. you should think about it like this, your dad is trying to push you in one way too much and you are losing the balance causing you to fall, now if you start doing exactly like you would feel at the moment you would go too far on the other way and you would just fall in the other direction. like your dad is trying to get you live your life in certain way that you cant enjoy, his way isnt the wrong way when you look at it objectively(because you get things done and your life in order(the Te way)), but its not your way because your way is going how you feel is the right way. but if you go purely on how you feel about things and rebel against everything your dad says, you might feel its fun for a while, but you will fall in the end because you have to maintain some sort of order in your life and having realistic goals etc. What you need to do is to maintain this Te, but manage it thru your Fi. try to find things that you enjoy doing that are good for getting your life together. dont do things with your life just because your dad tells you to do them, but dont refuse them instantly, try to see if it fits to you and do they take your life where you want it to go.
your dad should support you to find your own way instead of making you to go his way. you should tell him that, and that you wont compromise on that. you should refuse his way, but you should also tell him that if you go doing things purely on your way there is greater chance that you will fail without him supporting you. since he is an istj he thinks that your way will automatically make you fail in life, he just cant see that there can be another way where you can accomplish things.
you arent kid anymore even tho your dad keeps telling you that. you just seem like a kid to him because you cant do things properly exactly his way.
its not going to help if you just start yelling at your dad that he cant do things right because he would just see you as immature brat who just wont get what you should do, instead you should try to reason with him or he wont get you. you should also try to speak to your mom about this and tell her and your dad how serious this thing is and that this is a huge deal to you.
someone told my mom once that the most important thing parents to do is make themselves useless. i think this is very true and your dad is not doing this because he is not really teaching you to get our life together
if you can see that this is the problem i can try to help you find ways how you could reason these things with him or try to guide you in some other things related.