Some people never dare to write because they worry that people will think less of them if they fail to sell their novel or screenplay.
Here's both the good news and the bad news: nobody cares.
People spend far less time thinking about you then you think they do.
Let’s face it, we’re all concerned mostly with one person: ourselves.
Next, we think about our immediate family and our inner circle of friends.
After that…not so much. We may briefly consider why a particular acquaintance makes such bad choices of romantic partners, or why another one seems to be drinking more these days, or why the woman who lives next door doesn’t get a wig to cover that bald spot. A few seconds later we realize we’re hungry or we see a headline that intrigues us and those other thoughts are gone.
Frankly, whether you have success or not as a writer will occupy nobody’s thoughts for very long.
If you succeed they’ll be happy for you (or jealous of you) for a few minutes, then their thoughts and lives will move on. If you fail, the nice ones will think "too bad, maybe the next one will do better." If they're not nice, they may feel relieved that you didn't have success that could overshadow them.
The ones who do care may or may not understand what writing means to you. You can try to educate them. Sometimes that works, sometimes not.
If not, you can at least get them to stop being critical—most of the time.
If that doesn’t work, minimize the amount of time you spend with them if they are friends.
If they are family members you can’t escape, cut them some slack and maybe try to get them more interested in something of their own.
The people who will care are the people who read your book or see the film you wrote and are moved by it. Probably you'll never hear of it, but you will have changed their lives for the better in some small way. Maybe even in some not-so-small way--for instance, many lawyers who worked on behalf of civil rights said they were inspired by reading To Kill A Mockingbird or seeing the film version.
Before you have a success like that you may produce a number of projects that don't see the light of day. When you look back on those from a position of success you'll know the sacrifices were well worth it...and you'll be glad that you didn't let a fear of other people's opinions stop you.
(If you'd like some inspiration as well as practical tips on writing, get a copy of Your Creative Writing Masterclass. It features writing advice from the great authors, including Dickens, Twain, and Austen as well as more modern masters like F. Scott Fitzgerald, Hemingway and Vonnegut. Their down to earth advice and the example they set will inspire you. You can get the book from Amazon or your other favorite bookseller.)