First, go crazy. This is an important first step. You will need to establish a high stress, emotionally difficult line beyond which very few things can go. Once that is established you can compare "now" with "then." The "now" will inevitably look better and make you feel calmer.
Second, establish a schedule. You will need help in doing this. The doctors will be kind enought to determine the chemo schedule. You will need to keep track of it. Have a team of very special friends (and one sister) organize your life by setting up a meal delivers, child pick up and drop offs. Find friends to paint your room, do grocery shopping and call/email on a regular basis to check in. Establish a normal routine. The routine will look nothing like your old routine but the important thing is it will be a routine. Your spport team will most likely make you write down the following: an "average" day with the kids, school schedules with directions, how and what to pack to lunch, etc. They will buy you a huge calendar that becomes the "bible" of the house so you don't forget anything. They will also gently ask about your will and make sure you have it updated. Your PDA will become irrelevant.
Third, get pissed off at somebody that is not the lymphoma patient. It can be friends who have suddenly "disappeared" not emailing or calling to say they are thinking of you or just the slow driver who does not know the kind of pressure you are under. It's important for you to take it personally, becuase darn it, your husband has cancer.
Fourth, have a conversation with a sister-in-law where you realize that you are honestly mad that after all the work, the stress, the hysterics as well as the tears your husband has not been VOILA! cured. Order demands results. The result desired is total cure. Start to cry and understand for the umpteenth time, in what will be a line of a thousand and a thousand upmteenths, how sad, scared and tired you are. And how very much you want more than anything else in the world for this to be over. Obviously, these steps don't work. Crap.