BS here. The main tools for you now are patience and perseverance. You ought to expect his questions to continue apace for at least a year, possibly two or even three years. You should plan to answer them patiently and thoroughly as you have.
Gently, there is no meaningful distinction between limerence and love, to the extent there is one, in the heart of a BS. You told another man you loved him. Presumably, that was your subjective truth at that time. That is all that matters. Trying to convince your BH that you did not mean what you literally stated is a form of minimizing, which is the most common fallback of a wayward spouse.
Which leads me to my main point. There are two parallel things that must occur for R to succeed:
1. The WS must figure out her "why's" -- figure out what was broken in you and fix it. The goal is to make your BS feel safe. That you won't have another A. To that end, you need to own the truth of your betrayal. Saying to your AP "I love you" in writing, and then trying to convince your WH that you were lying to that AP, that is not the recipe to making your BH feel safe. "I was lying to you then. I was lying to my AP then. I might be lying to you now." Your BH is going to legitimately wonder if it is possible for you to tell the truth, ever.
He saw all of my texts to my AP which contained significant sexual and romantic detail. How can I convince them those text messages were not true when he saw them with his own eyes?
Why would you try to convince your BH of this? Were you lying to your AP? I doubt it. That was your subjective truth at the time you said it. You will be better served by owning your truth rather than trying to minimize it. I can assure you that there is nothing more frustrating to a BH than a WW who stubbornly insists on minimizing.
Here is another way of looking at it. Your BH is eating a shit sandwich that you prepared and fed him. He's gagging on the taste and wondering whether he can even bear being in the same room with you after realizing that you did something so awful to him. Do you think it helps him if you now try to say that you didn't really mean it when you did this?
2. The ephemeral matter of the heart. Your BH has to believe, in his heart, that your love and desire for him are true and sincere. There is no formula for this, but it is demonstrated through your acts, not your words.
One of the worst things you can do is ask if/when he is going to "get over" something relating to your A. You should assume he will never "get over" it. You should expect that, 30 years from now, if you are still married, if a heated argument comes up, he will throw the A in your face. I can almost assure you that the pain and anger of the A will never fully go away. You must accept that your actions have permanently altered your marriage. If you successfully R, your new marriage will be different than the old one, and the A will be a permanent "plus one" in the new marriage. Period.
Again, this is yours to own. One of the arrows in your quiver of apologies that you owe your BH is the reality that you destroyed the blind trust of the old marriage. In its stead, the best you can offer him, on your best day, is a marriage that will be permanently stained and tainted with the sting of infidelity. It's like that ugly water ring on the beloved antique sideboard, where your jerk of a drunken uncle spilled a drink and didn't clean it up, leaving it there all night to soak into the wood. For the rest of your life, you will look at that stain, and no matter how much you polish and buff it, the stain will always be visible.
I will close with a couple of suggestions. First, if you haven't already, read "How to Help Your Spouse Heal from Your Affair" by Linda MacDonald. Also, to the Healing Library (yellow box, top left of this page) and read "Joseph's Letter".
Many couples here on SI have found that a useful and fruitful path to R involves the WS preparing a written, detailed timeline of the A. This should include all of the "dirty details" and it should start from the moment you first met the AP. It should include your subjective emotional memories, such as when the AP first caught your eye as a possible sex partner, what you were thinking and feeling the first time you decided to have sex with the AP, what you thought and felt the first time you saw your BH after that sex, etc. This should be a working document that you build and add to along with your BH. It should also include family details, such as milestone events with kids as they relate to details of the A (i.e. -- were you texting or sexting with the AP while the family was having dinner, or away on vacation?).
[This message edited by Butforthegrace at 9:46 AM, December 31st (Monday)]