When you say your partner's cancer is terminal it doesn't tell us if he is expected to survive for a short time or a long time. If it is only a short time I think it would be harder for you to complain about your cancer. One place you can whinge or whatever is here.If you feel it may help the Cancer Council provides face-to -face or phone counselling ,5 sessions free of charge for a cancer related problem. I suggest you ring them.
I am sorry that you are in this difficult situation ,facing losing your partner and not being able to express your feelings about your cancer .
Have you had surgery and /or radiation? What treatment had your partner had?