At first you said that you think the divorce can be amicable but then later on you say when he feel hurt he gets selfish & won't consider the kids & this divorce isn't something you have even discussed with him past the first threat of it......

I think you will definitely need a lawyer to see to your best interests personally. I know how just plain STUPID my husband got every time I pushed for a divorce. Honestly it took me 13 years to finally walk out of there. I didn't know if it was the right choice. We had been married 20 years...but the marriage was bad the whole time, only reason I tolerated it was because I escaped into my career though I was always cleaning up the messes he made in our lives...it was nothing but constant fighting. Was so miserable after I my career ended with the crash of aerospace in California....it made my depression that much worse to the point of so many suicide attempts I lost count as I felt it was mynonlybway to escape because he was being so stupid about getting a divorce.

You are probably just better off (from my own experience) just deciding to do it when you are ready rather than wondering as the misery only gets worse & if they really don't want the divorce they will make the process miserable & even more os a challenge....since you aren't in the discussion mode about it, there is probably a good reason why you aren't.