Anouk...just a word of support..believe it or not in about 3 years you won't believe how much your life will change from when you were married...well, actually I shouldn't assume that, sorry.
For ME, when I was married I had very few friends, was over worked at home and work, oppressed by an overbearing guy, and always had to work 3x as hard to get to my goals, not to mention the loneliness, financial fights, and selfishness.
Now..I am sooo much better off in so many ways. I've spent 3 years healing and rebuilding. I have amazing career opportunities, work on my MBA p/t, study piano, participate at my church (ex-DH was an atheist, church wasn't in my life), spend quality time taking care of my kids and house, am in control of all the money coming in and leaving the house, and I am so comfortable I got a dog! I have a ton of friends now from work, church, and school. I get invited to lots of things and life is just so much better. I do date but I'll tell you, I am much more selective now.
It is hard being a single mom BUT the thing to think about is sometimes our dreams are bigger than the environment we are in so we need to change that environment. Your kids will understand your running around because they will see how hard you work for them and all that you accomplish.
Honestly, being a single mom has made me so vigilant about the time I do spend with them and the role model I am.
Good luck to you, I'm sending you strength...