I am from Bangladesh. I have been living in Germany with student status from August 2011 to 2014, refugee applicant status from 2014 to 2016 and Duldung status since 2016. From 2011 to 2014 I was a student in a university in Germany but I did not finish my studies. After leaving the university, I applied for asylum. And I ended up getting Duldung to my frustration. I realised my mistake of leaving the university and I decided to go back to the same university to finish the same degree from where I had left. I rejoined the university in February 2018. On my duldung, it's written that I am allowed to study. I do not get any sort of government support and I support myself from my savings and from the money sent to me by my parents. I do not like getting support from the government.
I have two questions:
1). Is it possible to shift to Aufenthantstitel from Duldung now?
2). Considering my situation, When can I apply for citizenship in Germany?