I don want 2 study doctor as iwant to study astrophysics but i dont know if it is secure ?plz u change my life?

I have completed my 2 and preparing for MBBS entrance exam.but i think space science is more suited to me.but i dont know where to apply for it , will i get proper job ,will i be sustain my life,will have to regret to this decision whole life. I am in nepal , there are no any place to study astrophysics , i have to go abroad. how much it will cost....can we get scholarships. There is one in this field to ask about how is this proffesion, where do we get job etc. My parent say that iam free to choose my future, but i know they fear it as they know other profession beside doctor may not be sexure for me. I dont want to read any other subjects beside astrophysics or doctor?, plz someone help me. Its a very big deal to me. It would be gret if u r related to this proffesion.