The only advice I have for people with mental blocks is… drink two beer. Just enough to help loosen those mental blocks without severely affecting your coordination or balance, then try letting go of your husbands hand.
As for the knees that sounds very familiar. When I was training for RTL (unicycle race) I my knees started to get really sore and it got to the point that I not only could not ride but run or even walk without severe pain. 6 weeks and as many doctors latter I finally met a doc that took me seriously and knew what he was talking about.
He told me I had a muscle imbalance in my quads. He said that it was a common imbalance for both cyclists and runners. I was unicycling 100-150km per week and running 10-20.
To correct it he told me to sit in a chair and just raise my foot flexing the knee ten times in a row three times a day. Two days latter I was walking without pain for the first time in over a month and four days latter I was running and riding pain free.
Your knee problems may not be the same as mine but that very simple exercise did wonders for me.
Welcome to the forums and keep us updated on your progress!
ERIC