Needless to say this has put quite a strain on
life in general.
I certainly can empathize with the difficulties you are both going through.
Being that your husband is younger than you by 9 years could also mean that under normal healthy circumstances his sex drive might be stronger than yours at this time anyway. Nonetheless, this does not mean that your "love drive" would or should be any different.
What I often hear from people who are disabled is that it is more important for the disabled person to satisfy their partner than for the disabled person to be satisfied . Generally the root of this comes down to guilt and major stress at bed time. Realizing that your physically painful disorders do not allow for the "spontaneous sex" your husband is being loving to you and considerate of your pain. You are blessed.
You mentioned that you would be wiped out for 24 hours after you had sex if you were able to have sex. Barb, I presume like most others in similar situations as you are in, there are probably things in life that wipe you out for 24 hours that you do because you are not given any other choice in the matter. This could be showering, tidying up the house, going to the store, preparing a meal etc. Sometimes, you probably even wipe out from doing nothing at all. Perhaps to plan on a 24 hour wipe out for something that is worth it and could be enjoyable would put less stress and worry on the entire issue. I have heard that many people with Chronic Pain
Disorders deal with things that they absolutely have to do this way. There is a big difference when you de-stress yourself and wipe out than when you are stressed and wipe out. The de-stressing by planning a restful day the day after an intimate evening will also lessen your pain, as stress only increases pain.
With your having MCS, I would strongly suggest that you do NOT use any fragranced products, candles, room fresheners, body oils, etc. to create a mood in your bedroom as this will put the flame out before it even gets ignited.
Perhaps a physical gesture from you to your husband (to let him know it is ok) would be helpful to send him the message that you are willing and in the mood. By touching him, it is almost like giving him the green light that it is ok for him to touch you. A gentle guide with your hand on his will show him the OK places to touch that are not as painful as the others.
Even if you do not totally succeed in a full sexual encounter, you will have a great feeling because you have attempted and with continued attempts the stressors will lessen and you will find a way to ultimately and intimately please each other. Though it may not be the same way that you used to please each other, you will feel satisfied instead of frustrated and know that it is not give up time it is get creative and go slowly time. Your love is strong, do not give up. I am not familiar with any specific literature/books on this issue.
I wish you well, please write back and let me know how you are doing.