Its a tough road, no doubt about that, but you and your boys will emerge the stronger for it. And if there is a positive i'm sure your boys have learnt a lot from the poor example your H has set and the good example you have which will help them find happiness in their own future relationships.
When all is said and done you will be fine and you'll be happy.
Have a great day
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress