When to divorce...is there ever an easier timeframe for the kids?

I met my husband immediately after his divorce. I was a professional and so was he, but he was living with his parents, with his clothes in a Hefty bag, and I had my own condo. He had two children, very young at the time, and a staggering ($2K+/-) monthly support payment, w/a $65K income. The ex never worked, so was clified a 'displaced homemaker.' Regardless, I got to know him and while marrying a divorced man with 2 kids was not high on my list, I focused on his potential as a professional - - to grow and succeed. I became pregnant. I agreed to marry, and my dreams were shattered. We now have two sons who are the core of my life. Regardless of how I have helped my husband cover his obligations over the years, he remains aloof toward me - showing attention only to our sons. I've maintained a full-time career through it alll, but remain empty inside. Given our boys are young, is there ever an easier time to divorce? I just can't live this way for the sake of the children.