You want some advice? Work on your communication with your wife. Let her lead the relationship and affirm that you will trust her judgement. Be an amazing husband in all other regards and make life as stress free as possible. Do NOT make this about you. You will fail miserably, and it will end in tears. As a cuckold you won't get to make the rules. You submit and obey them, or this isn't for you.
But cheer up because the Bull doesn't make the rules either. They are made by the wife. While a bull can respectfully decline a request, they don't get to force the wife to do anything they want. If your wife says "The Bull has demanded that I only have sex with you on your birthday and you'll be wearing two condoms so you aren't really touching me." That isn't coming from the Bull. Your WIFE had to consent and agree with making that imposition upon your relationship.
If she wants to do something, she is going to do it. You can't "halfway" give your wife sexual liberation and freedom. She is going to do things with another man that she doesn't do with you. You are in a completely different relationship type. If you are a cuck, chances are you have never been rough with her or dominated her in bed. Maybe, she's been secretly desperately wanting a stud to rearrange her insides and choke her while she climaxes and soaks the bed with her orgasm? I understand it's hard to hear that. but it's only going to happen if SHE wants that in her sexual relationship. Once you decide to become a cuckold, you must accept that her sexual relationship with another man is none of your concern anymore. Sure, if he is abusing her against her will, gaslighting her, or unduly interfering with your marriage -- then definitely take your testicles out of your wife's underwear drawer and strap them on for a confrontation. But otherwise, you need to let go and trust her judgement. Best thing you can do is be unconditionally supportive.
If you want some advice that might save your marriage and make you a happy cuckold, then listen up. Ditch all the effort and energy you are spending creating your FAP contract, and instead refocus it on being a better husband. Do the things she has been wanting done around the house, don't expect praise for doing chores. When she says she really doesn't know what she wants for dinner, be smart and remember she talked about this new sushi restaurant last week or that she was craving tacos a few days ago. Half of communication is LISTENING. Sadly, too few men do that well.
Want another pro-tip? Take much better care of yourself. If you aren't trying to be the best, and fittest version of yourself then it's an insult to her. You are saying she isn't worth putting in the effort to look good for her. If you think that combing that receding hairline forward is fooling anyone, it isn't. It makes you look week. Man up and shave your head. You'll get more respect as Mr. Clean than as Friar Tuck.
Take those hours you spend in crafting the "Perfect Iron Clad Cuckolding-Hotwife Agreement" and put them towards making her feel how devoted you are on a consistent basis. Be a doting loving husband always, not just when you are horny. Take every opportunity to build her up because she's going to need that confidence and feeling of unconditional support to enter the dating world again. I've slept with some amazing wives with extra weight or sagging breasts. Easily the best sexual partners I've ever had. They responded so well to being told they are beautiful and worthy of my affection and attention. WHY? Because most cuckolds want to force a narrative based on porn addiction. Instead, they should be making their wives feel beautiful and desirable every day.