[Mabus]

A few problems:
1) You have no "compelling public interest" for the transformative work to exist.
2) Your usage is not a parody, nor for purely informative or educational purposes.
3) Amount and Substantiality of the original work is extensive.
4) A modified DIKU is still available for sale. Your usage could cause harm.
5) The main body of DIKU is "a multi-user online text game", as is your derived work.
6) You lost any "fair use" when you violated the software license.

You're grasping at straws when you are trying to claim it as a "transformative work".

Also remember that software is not art and music. Courts have given more leeway to artists then to software developers, as deriving a work in art deals with impressions while using another coder's code (and claiming it as your own) is usually considered theft and/or piracy.

And then there is that whole sticky issue that US Copyright Law does not apply with DIKU. You might want to check into "Directive 2001/29/EC of the European Parliament and of the Council of 22 May 2001 on the harmonisation of certain aspects of copyright and related rights in the information society " and "Copyright law of the European Union" (as well as treaties between the US and the European Union dealing with intellectual property).

I will leave you with this:
There are places that offer free mental health screening and aid. There is nothing wrong with having issues. You may want to seek help.