is there such a thing as expense deductibles? and if you are in debt and working to pay of debt are you mechuyav to give maaser or are you considered an oni? and can you give maaser to oneself?
Aaseh lecha Rav! If you dont have a Rav you can ask this type of question you should try to find one, sure you can call any posek and get a psak but you should have a Rav that knows you for these and all questions. If you dont live in a makom torah and you need to speak to a rav, I and im sure ywn can provide some contact info. Hatzlacha!