changed minecraft username

[amber stream]

I'm logged in with the same account but I changed my username from lizard_king_7 to kepler_62f. Can I get back the inventory and /home I had before? Server seems to recognize me as a different player. Players online said to ask @marble thistle for help.
To clarify this is with regards to the betacraft multiplayer server

[marble thistle]

join now (or ping me when you do)

you should have your inv back