I have an italian student visa but i have changed my mind not to go for masters due to some personal reasons. Will the unused visa be a problem for me applying for other schengen countries in future?
Generally speaking, an unused visa is no problem. You should not be surprised, however, if questions about it come up. As long as you have a reasonable explanation, which you seem to have, the matter will likely end there.
I know someone who was about to immigrate to Canada when she found a job in another country. She no longer needs a visa to visit Canada, but when she did, her visa interviews always included a question about why she never immigrated. The interviewer always accepted her explanation about finding the job.