What does “gone into myself, won’t be back soon” mean?

This phrase likely means that the speaker is in a period of self-reflection and introspection, and that they will be taking some time away from their normal activities in order to examine their thoughts and feelings. It could be interpreted as meaning that the person is taking a break from the world and their daily life in order to focus on themselves and their own needs. This could be a positive thing, as it can provide an opportunity to gain insight and clarity about oneself and one's life. It could also be a sign of depression or anxiety, as it could indicate that the person is feeling overwhelmed and needs some time to sort out their thoughts and emotions. In either case, it is important to recognize that this phrase could be a sign that the person needs some support and understanding from their friends and family.