I wanted to answer all the rude and unhelpful comments in this thread, but then I looked back and decided it would take too long. Many comments here are small-minded.
There are many reasons to be dissatisfied with life in Hawaii. It’s remote and prohibitively expensive to travel even between islands, let alone the mainland. For landlubbers, you should know the first rule that everyone is taught here: the ocean is not your friend. People die in the ocean often, islanders and dumb tourists alike.
Life in Hawaii is outrageously expensive. The cost of living is 30% higher than the mainland, but wages do not match that difference.
If you don’t live on Oahu, there’s not a lot to do. Maui is dominated by hotels. The Big Island is very rural, and Kauai is simply small. Relatively speaking, all the islands are small. You can even drive the Belt Highway around the whole of the Big Island in 5 hours or less. Hawaii is not a big place.
To answer the question, let me suggest volunteering. Go to your library, walk up to the counter, and ask them how you could help. It will give you something to do that you will feel good about, and it will take you outside your head. If the library doesn’t appeal to you, call your county building and ask them for some worthy local charities that need help.
Other than that, I recommend reading, writing, journaling, blogging, taking classes at the local community college, teaching yourself to cook new things, etc. Explore the things you can accomplish indoors.