Lisa,
Mabey Bill wants to get it while he can, (or give it to you while he can) worried about what will happen to him as he goes through treatment.

Everyone's different how they react to treatment.

Some of the guys here on the forum had a fairly short period of down time, and a quick libido return. Remember what Gary said, during chemo, you need a condom due to the toxicity.

I'm sure you'll find that this will not even become an issue. The intimacy you will experience with him during this rough road ahead, sex or no sex, will be profoundly like no other. Like Gary said, "all encompassing".

Expect that he will have mood swings that will be difficult to cope with. Expect that you may not have the ability to help him on some occasions.
Expect that this may depress you. Continue to do the things that lifted your spirits before Bill was diagnosed. Don't feel guilty for protecting your well being. You have to, and doing so will help Bill feel better too.

Here's an example, I was in the similar situation you just described, getting depressed, not knowing how to help, all the ups and downs that are so highly emotionaly packed.
Okay, before diagnosis I used to like to get my nails done and a pedicure. It always made me feel good and I got a lot of mileage out of it. So then, I'm feeling like a selfish shrew to be so self absorbed during this critical time for my husband. Guilt brought more bad feelings and I'm like a time bomb, ready to cry any moment over nothing, but holding it in. Well, one day it fell out, I'm sobbing and asking if he would think I was awful for wanting to go do this selfish vanity thing. Surprisingly, he was so encouraged by this and urged me to go. I did and I got that happy little lift I hoped for and a lot of mileage from it as hoped for.
I was equally surprised to see one of the guys (who had the diagnosis) on this forum post about how happy he was when his wife went to get her toes painted. He never knew how much it made her feel good. He said something about, for the relatively inexpensive outing, it was worth far more than he would have imagined. His wife's well being was directly related to his well being.

Hang in there.... You'll get through this.
We're here for you.

Ginny