one week is to short, one month would be better. i would do 50 crunches then a one min plank, do this 4-5 times in a row, then work the side ab by doing 50 side crunches and then 50 lag and pelvis thrusts do this 4-5 times and then end it with one last plank for as long as you can hold it. i would tell you to do this ones every day like in the morning but because you waited so long and now only have one week, i say you do this 2 times a day ones in the morning and ones at night.
You cannot rush your body to see results, that is impossible, not even 1% of chance that will happen, you need to take it slow and at your own paste. do whatever you please kid but if you don't want end up in the hospital then don't rush it.