Hi BlueSkyGirl. Welcome to PC. I can tell you're hurting and confused and I know it is difficult to be in such a place.

I also know how it feels when you're going through a tough place mentally and emotionally and you also need to be a parent at the same time. That can be overwhelming. I also have experience with abuse. All of that combined is a lot to deal with.
You've mentioned a void several times. I don't really find it important to weigh in on how you've attempted to fill it in the past other than to say the solution turned out to be impermanent each time. If it were me, I'd take a step back and work with these feelings of emptiness for a while.
We are all whole and complete just as we are. Feelings of a state of void are a perception. They come in phases and they are a natural occurrence. Everyone has been there and will periodically be there. It is a necessary part of growth like the winter that gives way to spring. Winter offers a valuable opportunity to rest and let go of the past.
So, I'd spend time with the feelings and determine why there is a fear of being alone. That fear will move with you wherever you go until you address it. If you are able to find happiness in your marriage, it will not come without filling this void for yourself.
Try not to think of it as a dark and scary place. Perhaps consider it as a cocoon that allows you to rest, let go of the pieces of yourself that aren't working and then emerge when you're ready. You need time to figure out how to be complete on your own and then you can match that with someone else. The goal is to be with someone who compliments your features, not someone who fills in holes. Someone who challenges you and expands you, not someone who leaves you empty when things aren't working. You need to determine what you wish to be on your own regardless of the people around you.
Additionally, I think family therapy may be worth looking into. Perhaps couples therapy and then maybe sessions with the kids depending on their experiences with the abuse. This may take a while because it can be challenging to find the right therapist. Just feel it out and work with someone you and your husband feel compliments your own instincts and intuition about what you need to address.
You're right, abuse is negative in all its forms. We allow for abuse for various reasons and we in turn abuse others in various forms. It is a powerful learning experience. If you widen your perspective, you may see how some of your own behaviors have abused your husband's trust, heart and mind. The roles are fluid and it is important to understand what attracts us to those experiences so that we can see our patterns, forgive ourselves and find ways to generate better experiences.
I think it is also important to have a plan to address the mood swings. They can cloud our judgment and our perception of our state and abilities. There are lots of ways to do this and only you can decide the right route to take. The goal becomes finding ways to be honest with ourselves or finding people we can trust to offer insight when we cannot see correctly. At least for me, I was unable to properly determine what steps I needed to take to reshape my life until I was in a more balanced place. At that point I was able to better assess myself and develop a strategy to move forward.
It feels as though some perspectives here have felt offensive. I know that's uncomfortable. I do not intend to offend you. Anything that triggered you probably holds a clue to an area worth digging into on your own. Try not to take it too personally. Individuals here are working with a tiny subset of information about your story and are sometimes coming from a place of experience, pain and wisdom from their own lives. Perhaps just try to look at why you were triggered and see how it relates to any feelings you have of fear, judgment, or any of those voids you feel. I wish you all the best.