Staying married for "papers"?

Does it sound completely insane to stay married just to finish the citizenship process? To be more specific, it's me who wants a divorce, and it's my husband that needs the papers. I want a divorce, I'm not happy with him. He's changed so much since we got married and has become a complete asshole. But I still want to help him get his papers fixed. Not only has he already spent thousands on the process but it would be beneficial to him and our family if he was "legal". He could get a better job and provide for his son better, and not have to worry about being deported and missing out on our son's life. I 100% want him to finish this process, I just don't know if it would be crazy to put myself through an unhappy marriage longer than I need to. Input please? No need to be rude. I'd like to hear respectful opinions and maybe similar situations. P.S. We've been married for 2 years and did NOT get married for papers, we married for love but have fallen apart since.