Firstly, being married doesn't have to be reason to hate your life and feel chained down and oppressed. You have to change that perspective you have of marriage.
Marriage doesn't need to be being pestered by your husband. It can be being supported, encouraged, loved, respected and cared for by your husband. Marriage also does not have to be something that impedes on your university studies, in fact it does not interfere with university at all. I have seen many of my friend get married whilst being in university and they are all studying whilst having that special someone in their life.
Us muslims are very unusual. We either have no issue with how the non-muslims have girlfriends and boyfriends during school and university OR we are envious of them and the fact that they have a significant other. But when it comes to a mature, responsible and practicing muslim who wants to be married during university everyone loses their minds. This is a talk for another day, but my point is marriage doesn't have to be a black mark on your life and limit your opportunities.
Secondly, 20 isn't too young. Theres no issue getting married at your age and I mean theres nothing inherently wrong with being 20 if you want to get married. If age is the only issue, then im here to tell you that there is no issue. Alas, you dont want to get married and thats ok too but if its just because of your age and stage in life, those dont necessarily have to be reasons to turn away from marriage.