It doesn't always have to awful and just something to be trudged through weighed down by your own guilt. Not at all.
Depending upon the reasons for your divorce & why your marriage doesn't work can play a large part. I was partly relieved, partly angry at him, partly afraid of him but happy to leave a rubbish marriage. It can be very liberating to start to regain your independence & not have to worry about what he wants & what he thinks & how this all affecting him.
Because I'm not a saint I found it also very satisfying when he discovered that the tracks he thought he'd hidden so well all came out into the open & he was finally unmasked & shown to be what he really was, rather than the front he presented to people.
One thing I remember vividly was going to see my lawyer for the very first time & realising that there was somebody on my side. There was somebody who would stand up for me & believe me & help me to not take his shit. I was so used to people saying that I had split the family up & that I was a bad mother for not keeping the family together etc etc that it was bloody wonderful to have my lawyer. I really hope its the same for you OP.
There are good & valid reasons why you are leaving him Samteds, keep hold of these & look forward to the future without him. You can do it, you can cope with all this & it will be surprisingly easy compared to the scenario that you're imagining. He may be difficult yes but get into the mindset of fuck him, its not all about him! Make yourself & your children your first priority (perhaps for years) & recognise that you are not responsible for his happiness or what he chooses to do from now on.
Grasp your future, you are carving it out for yourself & make it what you want it to be. Take little steps, don't get overwhelmed by the emotional hugeness of the concept of 'divorce' & just do what is required when its required.
Look forward to not living with him & not having to put up with him & the associated issues that are all to do with him! :) live for yourself :)