I commend you for asking this question now, I really do. It says a lot about you.
I think you are very lucky and have an amazingly generous dad. I do think you have been done a bit of disservice in the sense that you seem ill prepared at the moment to grasp the cost of fully supporting yourself. I would suggest you take some time to educate yourself on basic cost of living financing and budgeting as well as starting salaries in your field so that you can understand both what your father has funded and what it will/could cost you on a go forward basis. The best way to thank your father for the gift is to become financially independent and successful in your own field. That doesn’t happen overnight and without help, will likely mean a change in your standard of living. I think you need to do some homework to see what that might look like for you. I think that if a $100 car payment to your father and the loan payment scare you, you may owe it to yourself and your dad to have a really frank conversation about life expenses. Those are drops in the bucket. I suspect though that simply gaining employment and being able to make those 2 payment to your dad would be a huge start in the right direction towards that goal.
To answer your questions, you are in the very very very small minority of being funded like that through grad school and your brother, beyond. I would say it is not at all the norm. You are blessed to have had that advantage. Many families are unable to pay for undergrad without loans and even less, for graduate school and beyond. Many students are forced to settle for less than their first choice of schools to avoid loans or their parents having to take them. Others simply feel that graduate school and beyond should be the responsibility of the student if that is something they want. Others may also want their child to have “skin in the game” to know that their contribution isn’t taken for granted and the child has a vested interest in not only the degree but in finding gainful employment after graduation. Sometimes children that have had everything paid for do not have a sense of urgency regarding employment post graduation and want to wait for the “perfect” dream job versus one that may simply be decent but gets a career started. That wait can go on a long time for some as they may not feel they need to worry about paying their own bills yet.
There is no single answer and certainly no right one, every family is different. If your question is directed towards parents in a similar income bracket as your fathers you may well get a very different response than from a broader, larger audience. What my parents funded for me, versus my husband is quite different. What we will fund for our kids is also quite different (and even different for my kids versus my stepkids) but as a general rule the expectation for us for all of our kids, is that after graduation, you get a job and fend for yourself. Which is tough and new for most but part of the life experience (in our opinion) is suffering a bit and figuring out what you need, learning how to save and to move a career forward to get to the income level and lifestyle you want.
As to your question as to whether most kids would “let” their parents help them out if they wanted to? I think you might get some very different answers depending on the kid and their desire for independence. Some really would rather eat just top ramen than ask for help, or even take it unsolicited.
Congratulations on almost being done! That is quite an accomplishment.
but I will do the best I can.