Op - I have had OCD all my life but my CD contamination issues were triggered by me preparing to get pregnant / pregnancy. It is interesting you said you didn't have contamination OCD when you had your baby - even when it was during covid.
OCD is just another way for your body to deal with anxiety. Some people chew their nails - you have obsessive thoughts and actions.
What has helped me get over my OCD contamination as much as possible - is I passed it onto my children and I had to become a role model for them giving it up / reducing the behaviours. Children watch their parents to learn from them - your children will learn to manage their own anxiety the way you do - through OCD.
My son developed OCD around 8 and that's when I realised I had it and had therapy on the NHS giving up a lot of my behaviours....but unfortunately it was too late for my daughter who now sadly has severe debilitating OCD that will effect her for the rest of her life. As you know more than anyone - obsessive contamination thoughts are hard to ignore - try telling a child going through puberty and being in a school environment they should ignore their obsessive contamination thoughts.
If I could turn back the clock and realise I had OCD at the stage you have developed it - I would have medication or whatever I could to save my daughter's future. Some of my OCD contamination thoughts wer I would get sick or die if I ate certain things that had been in unusual environments or if I ate without washing my hands. When you realise you have a choice to do that or risk your child growing up with a debilitating mental illness - trust me it gives you the strength to overcome many OCD obsessive behaviours. I have deliberately said behaviours - but its harder to manage obsessive thoughts but there is a delay between an obsessive thought and the associated behaviour where you can challenge yourself and question do you really need to do the behaviour.
If your husband has not changed his hand washing behaviour since you first met him - there is no reason that anything bad will happen if he continues on how he is.
I would recommend you time how long your husband washes his hands and then how long you wash your hands and try each day to reduce your timing until you get to his level.
I think you would also find it think helpful for you to reflect on what it was that triggered your OCD contamination levels if you did not have this before. Sometimes changes in hormones like perimenopause and puberty can be triggers.
The annoying thing about OCD is that in life we are told we need to trust our instincts - but as people with OCD we can't trust our own thoughts. It would help if you are very clear with yourself what is an OCD thought and was is not. And start to pause after an OCD thought and tell yourself this is just your brain feeling anxious - what are you really anxious about?