If you love someone truly it's OK , but when the other person don't like you and when they don't have feelings on you, why do you insist them to love you! I think it's called a mental torture your doing for someone.
Only a gentleman understand the situation ,but some are born to torture others.
So please don't torture someone who is not interested, if you love them truly then just pray to God to bless your partner Or you wish them to come back to you. So Try to behave like a gentleman.