Am I entitled to seek a separation from my husband due to a lack of feeling safe with him, despite his saying that God will not bless me if I seek a divorce, and are the reasons mentioned sufficient for that?

Matters such as your not being invited to his brother's wedding do not justify seeking a divorce. It is the husband's duty to provide suitable housing for his wife, and it is not a condition that he owns it. However, abstaining from marital relations for a long period, causing harm to the wife, is a harm that justifies her seeking a divorce. It is best that you communicate with your husband and openly discuss your right to marital relations. If he has an ailment that prevents him from it, then he should seek treatment for it.