Face the reality….!
If someone has blocked you it simply symbolizes that person is saying you go away. He doesn’t wanna have any connectivity with you neither he wishes to have a communication so just face the reality.
Because the only way you can unblock yourself from someone else account on Instagram is by having to their account which is nearly impossible. Getting access to someone else profiles won’t be possible neither it’s wise or legal way to unblock yourself.
Instead of thinking such creepy things you should write an apology letter to the person who has blocked because that will be a more genuine and decent way of getting unblocked.