Considering filing bankruptcy on my house....

where to start.... i currently have 2 mortgages on my home. totaling to more than $400,000. my home will only appraise at around $300,000. i am completely upside down in this house! my mortgage went from $2,000 to a whopping $3,200. i've definitely had some hardship - my soon to be ex. filed bankruptcy and won, thus leaving me with a huge house payment which was only increased once the bank saw that he (my soon ex) was cleared of all debt - apparently this show instability to pay on my part - however, i had been paying the mortgage alone for a year before my ex actually got bankruptcy (the bank would not recognize this and increased my rate). i have cc debt which is why i have not been able to refinance....my ex was also cleared of this debt. i was not interested in filing bankruptcy for the sake of trying to keep my home, however, i do not know what other choice i have. i am littlerally "house poor" - i can barely afford my outrageous house payment and nothing else. in a few months i have decided to no longer pay my mortgage, file bankruptcy, and let the bank take my home. i feel like i have no options left. is filing bankruptcy my only choice? if i just continue to pay my 1st mortgage and not my second...what would happen? how long will it take for the bank to foreclose on my home? please help....