Changed my screen name. Lost all my contacts

Your account looks pretty brand new. Seems like you may have set up a new account rather than changing your username. Have you tried logging in with your old username/password?

You mean you got a new profile?

If you go back and re-open your old username account under the original name, it may have saved your old information since your old username is linked to your specific I.P. address, which means you are the original owner of that account and the system will recognize that fact.

Your profile is brand new, looks like you opened a whole new account rather than just change your name

If you take out a new account, you have become a new user once again, with no contacts or history.

They should still be under Social -> Following.

If you changed your username, why do you think your contacts would have been automatically saved?