I agree with justrae83, you are making the right choice, enough is enough, I was 47 when he left, we were married 16 years, I am surviving just fine and the pain does go away or reduces to a manageable size, just think of all the new wonderful experiences you are going to have.
Life gets better, it really does, it will feel weird at a times and the obsessions will come back some times strong but you can make it, you and your kids will be fine and finally happy.