Your husband has got some maturity issues of his own. Set a firm boundary over the writing issue. Your writings are private to you, and that's that. Put them in a secure place. When he asks to read them, say "No" and don't waffle around on it.

Married women having male "friends" is not such a hot idea. Get yourself some lady friends whom you can confide in. You and he should seek to socialize with other couples . . . jointly.