Hello, I am Rafael. Thanks for asking your question - I'm here to support you. (Information posted here is not private or confidential but public).
I am very sorry to know about this very painful and concerning situation.
I'd say that it would be overwhelming for most people in your shoes.
Could you please tell me for how long have been suffering this serious marital reality?You said he loves her mistress and only remains with you because of your children, which is very sad, but unhappily this is not an uncommon scenario. What gives you hope that you could heal your marriage and bring that spark into it, if you are aware that he does not love, but her and does not even like spending time with you, which is a very painful but conrete reality?
While I wait for your reply I'd like to say that for your marriage to heal and grow from this crisis, both of you would need to be able and willing to work on this process. This means he would have to choose to stay there with you not exclusively because of your children, but because he wants to work on your marital issues, and is willing to work on his personal problems that led to his affair.
Thank you for being here.
Thus if he stays there only because of your children, he would resent you, and it would wound you and your children too, since their happiness and well-being does not only depend on having your physical presence there with them, but on how each of you feel at the personal level and in your marital life.
Children's personality, minds, hearts and lives are literally shaped, not much by the words parents use in their education, but by the modeling they offer in the way they take care of their individual lives as adults, and share with each other as spouses. This is why even when parents try to provide good parenting and affection to their children, hiding their serious marital problems from them, such issues would still undermine what they offer to their children and the way they develop, grow and who they become as adults.
One of the most common issues observed in situations like this is how when children become adults, they perpetuate the same pattern, getting into infidelity, of becoming codependent and allowing neglect, abuse or manipulation, truly believing that because of children they should sacrifice themselves and take infidelity, abuse, neglect or any form of dysfunction, that such is their role, right or responsibility. For example a daughter could truly believe that it is her responsibility to afford all the pain and consequences from an abusive or neglectful husband because fo their children, and spend all or many years of her life suffering making such sacrifice" becayse of them. Unhappily the same pattern could be perpetuated by her own children as adults.
In case of sons, they could also learn that they have the right to betray their partners-wife, and that they need to be very skillful not be caught in order to benefit from their dual lives, but if that happens, they should leave or stay, following the same pattern their own father presented when they were little.
These are just examples of common consequences of dysfunctional families where spouses remain together, because of their children, while not truly working on their personal and marital issues.
The personal work is something each of you can and should do ideally with professional psychological support -psychotherapy, once each of you start such process, then marriage therapy could become very beneficial supporting you to work on the marital issues.
In individual psychotherapy you would explore and identify what was there in your feelings, words, choices and actions, that could have directly or indirectly contributed to the marital issues and crisis. Then you would work on making necessary changes on those areas with your therapist support. If both do this work, taking each of you responsibility for what depends on you, and focusing on healing and rebuilding your marriage, then marriage therapy would help you to develop better communication, mutual understanding, coping skills, deeper intimacy and trust and to improve other core areas which determine the level of health and fulfillment you create in your marriage.
Does it make sense?
Also consider reading some of these books, which could help you in this process:
Love Is Never Enough: How Couples Can Overcome Misunderstandings, Resolve Conflicts, and Solve Relationship Problems Through Cognitive Therapy
http://www.amazon.com/Love-Never-Enough-Misunderstandings-Relationship/dp/0060916044/ref=sr_1_1?ie=UTF8&qid=1381452535&sr=8-1&keywords=love+is+never+enoughI Love You But I Don't Trust You: The Complete Guide to Restoring Trust in Your Relationshiphttp://www.amazon.com/Love-You-But-Dont-Trust/dp/0425245314/ref=sr_1_sc_1?ie=UTF8&qid=1382986406&sr=8-1-spell&keywords=trust+relatiosnhipsBoundaries in Marriage http://www.amazon.com/Boundaries-Marriage-Henry-Cloud/dp/0310243149/ref=sr_1_14?s=books&ie=UTF8&qid=1385700565&sr=1-14&keywords=marriage+in-lawsShould I Stay or Should I Go?: A Guide to Knowing if Your Relationship Can--and Should--be Saved
You're welcome. Sure. Thanks.