I know, from personal experiences, that having an infirmed wife, whom you love dearly, is much better than the alternative.
Over time, I hope you can thank God for bringing her into your life. You can look at your son and see your wife's presence.
Most of all, you can live the life of which your wife would have been proud.
For now, may you find peace and comfort in knowing the time you have remaining here is temporary and YOU WILL reunite in a better place.
God bless you and your family.