i would be very careful of being so infatuated with a person that, you forego reason and judgment. You may do Salatul Istikhara however I am a little concerned with the level of infatuation here. It is said that you may get a sign, however if you cannot control your feelings and your nafs to the extent that it seems this marriage is your sole purpose in life then I would slow down quite a bit because the 'sign' you get could simply be your own feelings. She has explained to you she is not ready. That's where you stop and revisit your own life, your own goals, your own imaan etc and work on them because irrespective of whether this marriage occurs or not you will always need to be working on yourself, income, your own character etc. I have often seen brothers in your circumstance get taken advantage of owing to severe infatuation and getting involved in situations where it seemed to me they were not the decision-makers but were simply made to feel that way. you may not understand this all at the moment but I would urge you to step back and rethink what you are doing and your approach. You may come across an answer, possibly one you don't like but this is part of the journey. If this is still something you are going to pursue and you want it to work out, you know when the study and the financial issues will generally cease. At that time you take the proposal to parents/family members and take it from there. In the time between work on the things I have stated including health, income, becoming more competent, growing as a person, developing yourself personally and professionally so even if things go sour, you are not in a position where you are comprised to the extent of mental breakdown. I say this out of experience and care and nothing else. You can pray and do everything else you are doing, but also please make it easy on yourself because not even tomorrow is guaranteed.