What does みてえじゃ in this sentence mean ?
困ってるみてえじゃねえか。
It's just another example of the ai-to-ee sound change found mainly in dialectal or male speech, which is described here and here.
ai
ee
困ってるみてえじゃねえか is the same as 困ってるみたいじゃないか.
In case you don't know みたい, see this.
みてえじゃねえか is an unrefined expression of みたいじゃないか. It is frequently used in an ironic sense, so be careful to read the context.