Question: Will I be able to have normal intercourse and reach orgasm after my breast cancer treatments?
Answer: You should still have the same erotic feelings and be able to reach orgasm during intercourse, just as you did before. Remember that your treatment for breast cancer affected your breast, not your pelvic region -- with the exception of vaginal dryness.
Some women do have the tendency to maintain vaginal dryness for an extended period of time after chemotherapy -- particularly if they then embark on hormonal therapy shortly thereafter. So do go to the store; buy over-the-counter at your pharmacy various supplies that do provide extra vaginal moisture. They work extremely well.
If you try to go without, you're going to find that it is more difficult to reach orgasm if you are experiencing dryness. The more lubricated you are, the more relaxed you're going to feel and the easier it will be to accomplish that wonderful goal that you both share.