Hi saphubby and welcome to the club.
You will find reading and posting on this forum is the best therapy there is. Write all your frustrations here and you will sleep better and you’ll get a sympathetic response from people who share similar problems although mostly not quite as extreme. Of course the most significant events in your W's life are the death of your child and her dreadful illnesses and operations. Clearly someone with stresses like that is going to have sex well down the list of priorities unless they are very HD. That is going to take a lot of time and work to get through.
On the subject of sex before marriage I probably have the opposite view to you. My W and I were students and slept together on our first date (we had known each other casually for about a year before that). I can honestly say that the first year we were together was the best we have had. If you hold back on sex when you first meet you are missing out on the wave on animal passion that you feel as new lovers. We married almost three years later and by then our sex life had gone. I believed it was due to the stress she put herself under organising the wedding and worrying about her father who was ill, money, housing and you name it...
I have a feeling that weddings are the biggest passion killer ever invented. The pressure is on for the woman who has to worry about the dress, the church, the flowers, the guest list, etc.etc. Because it is organised (in English custom at least) by the woman and her parents, the groom can feel left out and on the sidelines and the bride can feel that he is being lazy and unhelpful. It is not a good start.
I have a son of 19 and a daughter of 16. I am not burdened by any religious belief and I will encourage them to be completely comfortable with any prospective partner particularly sexually before they marry because I know how much pain it has caused me in my life. If my children are not sexually at ease with their fiancé(e) well before their wedding day I hope I have the strength to suggest they call it off (of course I will be unlikely to know much about their sex lives).
SuperDave