capital gains tax on investment

i am in the middle of a divorce where both our names are on an investment account. this account has not been discussed as to who claims it and/or pays the tax, if any. i am claiming it because i'm not sure what to do with it. it has hit me with a big tax bill as it gained 40k last year. i only earned 32k from wages. i can't afford the tax bill (2.5k fed and 3.2K state) and don't know what to do. do i claim it? remove it? i'm lost and any help is appreciated.