post-partum weight

So I had finally lost all my extra weight and really proud .....first off I'm 4'10" tall and the first time i tried to lose weight i was at 145lbs....and that is a lot for someone my height.....in 4months i had lost the weight doing ridiculous amounts of exercise and incredible will-power against all foods bad for me... and then i had my first son. I ballooned up to 155lbs by the end of the pregnancy and then stayed at a steady weight of 130lbs there after. I wasnt exactly happy with my weight, but didnt have enough time to push myself to the extremes like I did before.....and then i had my second son, fortunately I only reached 155lbs again by the end of the term, but this time i am stuck at 140lbs....i have no clue how i am going to lose 30-40lbs, it just seems so impossible to get rid of the postpartum weight and I kind of want to give up. it has now been 6 months since my second son and I am only at 139lbs...the weird thing is, I am eating small healthy meals/snacks about 6 times throughout the day...Hopefully now that i have time to incorporate exercise, I'll be able to lose more weight *Sighs* well we'll see anyway...
Diana