Hi Kiki. I am so sorry for your loss of your little ones.
If I was you I would keep on the path of self confidence and keep with the exercise and healthy life style changes. They will continue to boost your self confidence in yourself. Short attainable goals that are so positive.
You also need to realize that your Husband cannot be trusted. That he will lie to you to cover his EA's or even PA's. You also need to learn the difference between snooping and verification. As you know he uses the computer for online sex. He knows you know this as well. He has turned this into you are the one who is not trusting. Where as it is he who has proven with his repeated actions over and over that he cannot be trusted. Some good gaslighting going on there. I would recommend you look at installing a keylogger to track all online activities on your home computers. Do not speak about it. Do not present it. Keep it for verification. He will most likely be moving these thing's further underground. So you will either accept that he is cheating and live within an open marriage. Or you are going to have to set boundaries on what is acceptable in your life and your marriage. Then it is up to H to decide if he wants to live within those boundaries. With boundaries comes choices and actions. If you do not uphold your boundaries then H learns that he can fool around and sleep with other women and the end result is that he will have a wife who will stroke his ego and change to what ever he wants as a better wife. This is the balance of the game that is currently being played at the moment. Right now it is rigged in his favour. So you have to work towards evening out the score. You do this through continual self-growth , greater confidence in yourself and rebuilding your self esteem. You cut out the R talks, skip the 5 love languages books for now. You prepare yourself for a single life with shared parenting. You get your finances in order. You gather your evidence. You set up your support groups. You get that all in order. Then you know that you will be fine if things do not work out. At the same time you work on what your boundaries are in the marriage and what issues you caused that you can correct within yourself. You work on those issues. You also determine what you want in a Husband and what you want in a relationship. What are the actions and choices you will make if they are not met or broken( MC , changing of jobs, no more hanging out with other women , full disclosure on all activities, D ). Then you live with your boundaries. Never negotiate them, only explain them. Then your H will have to make his own choices and decisions.
Which will be to acknowledge his weakness with the other sex. Openly rebuild the trust he destroyed. Verify that it is not being broken through repeatable actions and choices. Or the honorable choice and D instead of years of emotional abuse due to serial cheating.
That is the road map.
How long it takes you to get there is up to you.
But you are in control of what is acceptable in your life. There are a ton of good 180's there for you as you DB your marriage and improve yourself. Remember a 180 is something you try and track progress. Not all are directed at the Husband. Most are directed at the self. It does not matter what the H thinks about them on a day to day basis. What matters is tracking positive 180's in your life that you can track and notice how things change within your self and your interactions with others. Remove the focus from H. Place it upon yourself.
There are some great women here who have really rebuilt their self esteem, saved their marriages and/or themselves. There are some who became doormats for awhile before they woke up and realized that doing laundry , extra cooking, over sex and dressing the 9's for a cheating husband is a zero sum game that just erodes your mental health while stroking his ego. Seek them out and they can help you navigate these tough days.
Take Care.
Flowers always make people better, happier, and more helpful; they are sunshine, food and medicine for the soul. unconditional love is awesome!