Who owns the rights to the movie?

There is no easy answer to your question. It would depend on the type of agreement you signed with the studio. It is possible that the studio can claim some rights to your movie. Please have your agreement reviewed by a qualified attorney.

Ownership rights are set according to contractual agreement. Generally, filmmakers and producers jointly form a company specifically to operate and control the film. Then, that Company is the one who owns the film and the partners, by contract, divide out the specific participations of each person/entity involved in the film.

By not addressing the business side of the film business first, you've gotten yourself into a real mess. As the writer, you own the script. After that, any number of people and the film company can have a claim to at least some of the rights to the film. You need to have written agreements with everyone who's working on the project establishing their roles, responsibilities, salary or hourly wage or other payment plan, and transfer of any rights they may have to you. Funding the film does not necessarily grant you any rights other than the right to be repaid from any profits the film makes.

You need a lawyer on your production team. You will all negotiate on who owns what, and the lawyer will write up contracts that reflect this agreement. If you already signed any contracts or made any written or oral agreements, you will show those to the lawyer. The movie should probably have ownership shared in different percentages by you and the studio. There should be some way to reimburse the cameraman, actors, and others, perhaps with money and perhaps with a percentage of the movie. This will all go in the contracts.