What does 'one' do?
What a broad and general question!
First off, is your wife well?
Is this question lema'aseh? Or just theoretical?
I will assume the 'one' you refer to is yourself, and that this question is not at all theoretical. So:
Shlav 1:
Would the abstinence be for health or other such circumstances - or because she intentionally refuses to have sex with you? The response is a lot different, though some aspects of the 'problem' are the same.
Is your worry that you will have a hard time dealing with the fear of lack of sex?
Or do you believe that not having the opportunity for sex will lead to to sin?
Or are you afraid of being afraid of not ever being able to have sex again?
Shlav 2:
My wife and I had a significant period of voluntary sexual abstinence just because sex was becoming too big a deal. I was sober a bunch of years at that time (years earlier, we had the nasty kind of one-sided abstinence because she was shocked and angry and were way past that for many years then - so this was something entirely different).
Voluntary abstinence meant she went to the mikvah and we learned how to go to sleep together without getting sexual or lustful. More than a few months passed. We grew much, much closer than sex could have gotten us.
Because I am a bit ill.
Normal people probably do not need this. Hashem has already given us sexual abstinence every month (niddah) that we choose to do (so it is voluntary, as all of our avodas Hashem is ultimately voluntary (bechirah), even if we give up our voluntary-ness by the yir'as Shomayim of 'kofoh aleihem har k'gigis' then that giving up was still voluntary!). Hashemlikes periods of abstinence...but the four months+ of it - that is for sick people like me who want more peace of mind and are willing to give up a lot for it.
Peace is worth it.
But something tells me you are not looking for this, but are having some sort of problem that will take sex away from you.
Is your question about widowers - how do they stay clean for decades?
They do, you know...unless they were sexaholics to begin with and never got sober (sometimes we never know of them - many sexaholics are suffering secretly, and they are eventually going to be masturbating zaidy's, old talmidei chachomim, old amaratzim, etc.)
Gevalt. Can you be a bit more direct - or is this not the right venue, being an open forum? That may very well be. I respect that.
Or am I completely misreading you on this?
Best wishes, chaver!!