I don't know if anyone got back to you yet so I apologize for the delay if not. (I have been backlogged.)
I will try to help, from the perspective of a married man of about 25 years. You are starting over and there are generally bumps along the way, which typically are more difficult in the beginning (nobody can really prepare you for the first year), so you have to have patience with yourself.
You must learn how to let go and let God. Your problem is that you are over thinking this a bit and focusing on yourself too much. God gave us sex for the other, that means your wife will dictate what she needs in order to be close to you, and you will learn to read each other when you need intimate time together. It doesn't have to be planned, or spontaneous for that matter, it just has to be available to each other when you need it. If your schedule doesn't allow for spontaneity then schedule it. You must create that time and space. Your bodies will start to yearn for each other and your sex life will become better because, just like hunger is the best sauce in any recipe, your desire for each other, will help dictate the frequency and quality of your relations. (And don't forget, the main reason we have sex is to create families, so your need for sex will ebb and flow as your family grows as well.)
So, relax. Don't worry about performance issues, you should be able to laugh with your wife if things go more quickly than you had hoped, but do not leave her unsatisfied because you can finish her climax manually if she is left short. Or have another round. The bottom line is that sex should be a joy-filled, not anxiety-filled, occasion. Communication is always helpful, but you need not share every anxiety either, just give it to God. Ask for His help. God invented sex, He is not embarrassed by it, ashamed of it or opposed to it. He is opposed to abuse of this sacred gift given to husbands and wives that is exploited by others and misused by many. God delights in sex between two loving spouses because that is how he chose to bring new life into the world; life that has eternal potential.
In time you will get beyond this mental challenge, but also keep in mind that diabolical forces want to use your past sins against you. They will bring back memories and experiences to your present mind as a temptation and a weapon. This is the sad side effect of past sins.
But also realize that they lose power as we live in a state of grace and turn everything over to God. Rebuke the negative thoughts as if they are demons themselves and you can regain control over your mind (cf. Romans 12:1).