Hang on Lois. It really is somewhat simple, but the explanations are coming from various points in somebody's life journey. I can see how it is confusing - good on ya for sticking with it. I can see you do want to know.
I've been there. I wanted to know how to forgive. Or if I could forgive. I'm human. My brain and heart were screaming, "so she did x, y, z, and then some and continues to do so. But what about ME????" I talked to my pastor, my friends, my God, myself (that's helpful if not strange :))
I am a Christian. I have been told to forgive, but never really shown how by other people. It's easy when you watch others or hear stories. But it's harder when it's you and you come up with ideas about it such as "if I could just understand" or "if they would just stop poking at me and being hurtful" or "If my ex would just say they are sorry..." or ... The list could go on with things that are first.
When I die, I expect them to bury me face first so Dr Phil and Oprah and their types can kiss my a**. I find their pop psych to be detrimental and irresponsible. Just so you know where I'm coming from.
Forgiveness is NOT just for you. It's NOT just for...anyone except the person that needs to be forgiven. It has a side benefit of helping the person giving the forgiveness (depending on why they forgave - if for selfish reasons only, it has less value if you ask me; and often unresolved things that dangle along with it.) Forgiveness does not require anyone's input or action. It is yours to give or not to give. Period.
Trust as a gift to give? I hadn't thought of it that way, but I can see the wisdom. I also see the wisdom in trusting or distrusting when warranted. I can forgive and not trust nor forget. It would be foolish to forget or to trust unwisely (seems redundant I know, but think about it.) But the cycle of trust requires *somebody* to start, does it not? To take that leap of faith, somebody has to initiate the trust.
The anger? It doesn't go away when you forgive. It doesn't go away with trust rebuilding. The anger goes away when you get your perspective straightened out. When you get over your own disappointment at the events that took place. When you embrace what is vs what you wanted or expected and the gap in between. When you realize that you took a chance and it didn't work out as you expected, but that you'll be ok and likely better as you progress on your journey. When you realize we are all flawed creatures and although we may lie to somebody who trusted us, it doesn't diminish what we felt or wanted to be.
These are three separate yet intertwined items, Lois.
Letting it go is not easy when it's in your face all the time. When you haven't had a chance to regain your perspective. To let your own light shine. To let go of the hurts and expectations you *had*. Forgiveness of the other for not living up to the expectations is not that hard after you regain perspective. Forgiving yourself may be a little tougher Trust is the hardest because your concept of it is based on your past. That's understandable. It makes sense to do that, but the leap of faith is to rebuild trust when there is none there currently and the other person doesn't act the way you expect they should.
Crazy isn't it?
Re-think it though and it's not as crazy as it sounds...
Life's short. The goal is not to stay married to the same person and you'll therefore have a great life. The goal is to become fully human, to love your God and live a life that proves that out, and to hopefully share your life with a mate/companion that shares the outlook and journey with you.
Trust is the hardest because your concept of it is based on your past. That's understandable. It makes sense to do that, but the leap of faith is to rebuild trust when there is none there currently and the other person doesn't act the way you expect they should. 
