First, it is very unlikely your negative trust will be removed now.  Your actions caused you to get negative trust, and your words say you won't do it again. 

Actions speak louder than words!

What you need to do is ignore the trust, and continue in the forum as a helpful contributing member.  You may not be able to join a signature campaign, but that doesn't stop you from discussing and contributing.

After at least a couple months have passed, try PMing Hilariousandco and asking him for a second chance.

He didn't become a senior mod on this forum by being unreasonable.  Good luck!