Hi ashutosh, as both of u has gone through a serious relationship so its better for u to stay with her in future. If u are going to break ur relationship with her then it will true that u have used her both physical and mentally for ur happiness. So there is many problems will occur in every relationship but break up is not the solution. If u are truly loved her then ur heart will not let u to leave her. So think calmly and talk with her discuss ur problems with her, otherwise u will become a sole reason for destroying a girl’s life.