I'm so proud of you for sticking to your guns. Doing the right thing is not the same as doing the easy thing. The more practice you get with sticking to your boundaries, the easier and more natural it becomes.
Something helpful that I do is to NOT look too much at the big, overwhelming picture. focus on the details - the action steps you need to take. Move forward one detail at a time and you will get through it. Take it easy on yourself too. You have a right to be sad and hurt. But it doesn't have to paralyze you or destroy your life.
Post often! You'll find many people here to support you.
(((hugs)))