Verb conjugation of "diffuse" in English

Good luck and success in this new job. Please tell Anna that this morning I had a great Capuchino coffee and I had to think of her. The aroma reminded me of our vacation in Northern Italy.
Anyway, there are a lot of people on board and I no matter how high the waves may be, I always suffer from nausea or seasickness. I have not been on a small boat before. I will have to vomit.
Have you ever visited the U.S. before and if so, where have you been in the U.S.? I've been travelling in California, it was very amazing. We have traveled by car. Here are my corrections.