First, if you are innovative enough, you can make a career out of something you love no matter what. So don't give up on a dream if you are willing to make new paths.

Second, the military has wide use for engineers who also speak languages.

Third, the CIA and intelligence agencies have need of fluent speakers.

Fourth, academics for study focus upon linguistics, but usually aren't well paid.

Fifth, business has need of people with business skills that are also willing to live abroad and with language skills. Same for engineers.

Otherwise, keep it as a hobby.