Honest advice needed
Do i stay in a relationship just for the sake of the kids and not hurting anyone or do i do what will make me happy
It sounds like something happiness is on both sides of that equation and that you need to collect your thoughts on paper so that you can see the big picture, past present and future.
This process will help you see everything at once allowing you to choose levels of relevancy and give you perspective. It also makes the question seem like paperwork instead of an emotional and important decision, allowing you to think with more clarity.
Whatever you decide to do understand that your mind has created patterns based on your beliefs that your mind will gravitate towards and so whatever you choose it will be an adjustment.
Working it out on paper and formulating a firm decision will help you down the road when you question if you made the right choice or not.
Other questions that I would consider collecting my thoughts on are. WHAT IS LOVE? WHAT IS FREEDOM? WHAT IS HAPPINESS? Answering these questions not with the consideration of your relationship choices, but yourself. You live with you and will forever. Be someone you Love and are happy and FREE with.