those interest rates were killer. i cant comment on forebearance or IBR, but i have some suggestions. many foreign and domestic grad students survive on their stipends of 10-15k per year. some families live off of just that much as well. the trick is to be extremely frugal, buy only neccessities, always compare prices, dont eat out, give up your car, finding cheap housing. there are plenty of blogs on the internet about living cheaply to the extreme. if you can keep your spending below 15k per year, the residency salary of 45-50k before taxes should cover your loan payments. it can become tough to do especially if your residency is in an expensive city or if you need to support your family.
im not boasting, just sharing my experiences. i managed to pay off my loans after intern year but i cheated. i mooched off family members and stil do by living with them at various times. that cuts out housing and utilities for me, which can be 50% or more of annual expenses for many americans. it also reduced the cost of food, which is maybe #2 for some families. transportation is also a big expense and i biked a lot and have never owned my own car until this past year. i dont have undergrad loans because i went to an uncompetitive school and had enough merit based scholarships to cover most of the tuition. i worked and saved through high school and undergrad. i did not spend money on a new phone computer or video game system every year as my friends did. did not buy name brand clothing or any unecessaey items. no expensive vacations and rarely ate out. the savings plus my intern year salary paid off my med school loans. i also kindof cheated by staying in state for med school and got out just before they had a big tuition hike. planning my spending like that was not at all enjoyable but it got me through these ridiculously high costs of education in the US.
so my suggestions are to examine your expenses and cut wherever possible, especially with big items like housing. you can google more tips on blogs and forums. get rid of bad debt such as credit card balances, which usually have apr's of 12% and up. if you have different loans you can request to consolidate them: my brother did that and reduced his interest rate to 3.5% somehow.
if your spouse is making bank, then you're all set. i imagine that if you file joint income taxes, some of the alternative repayment plans will be unavailable to you. it probably won't hurt to try, though. just remember that you end up paying more interest in the long run with these plans. i also thought forebearsnce is awarded for life changing events such as disability, but i could be wrong