Age doesn't matter.... some of the best mothers I know happen to be those who got pregnant young (Zebrastripes for example). But I think you should take time to prepare before getting pregnant, like any TTCer thinking of getting pregnant no matter how old they are. Most of the time, you don't get the chance to make your baby's world just right before it arrives, they get sorta launched at you, and you have to make do... Trust me when you have your child, you will realise how massively important they are and how unworthy you are... and how they deserve the best in the world...
For one, getting a job, working there for a while, before getting pregnant so that you qualify for SMP... rather than living off measly government hand outs because you are not over 18 and living with a partner, so the government will screw you over again. Also going to college with a baby is a pain in the bum, tbh.. its do able... but its not easy... I went to college after I had Tia and financially it was hard... There were many sacrifices I had to make, including missing several meals, just so that I could afford nappies, rent, gas and electric. It might be advisable to wait till you are living together before trying for a baby, just so you can see how your finances go...
Also with a Chronic liver condition, you need to think seriously about how that will effect your pregnancy too... I say this because I have Crohn's disease, and I had several long talks with my consultants before I even began trying for a baby this time round... I wanted to make sure I got all my drugs and treatment right so as not to harm the baby, and what complications could occur should I have issues with my disease. Have you spoken to your consultant at all?
I know that both me and DH could care for a child both physically and mentally with a third child and it is something we both want and have talked about... but we know that financially that would put a huge strain on the household and our relationship, and we do live together and he has a full time well paid job, we have savings.... Doesn't mean that we are not capable, that we aren't responsible enough, it just means that we know at this current moment in time, it's not practical.. and when you have your baby you will see how much finances come to play in your life... especially around xmas times.
and you don't want to be begging and borrowing off your parents all the time... you want to be responsible and independent. You want to be able to say... this is my baby and I raised them myself. Of course parents help (buying pressies etc).... but its a great feeling doing it alone.