[belorn]

The simple and direct answer is to distribute the combined whole work under GPL, while distributing the parts your have written under MIT.

The more complex answer is a question. Why did you choose MIT? If you want people to use the parts you have written under a permissive license, then the setup above will allow that. If your intention is for people to use the whole combined project under the MIT then the only legal option is to remove the pHash dependency and either rewrite that part of find a alternative dependency that provide the same functionality. If you just picked the license randomly then simply switching to GPL will solve the issue.

As for free lawyers, I think the software freedom Conservancy might answer such questions at https://sfconservancy.org/about/contact/