What does i would much rather give up all the remainder and be spared the painful anxiety it gives me when you even talk of venturing again on the faithless deep mean?

The speaker expresses a strong desire to avoid the distress and anxiety caused by the thought of someone risking their safety by venturing out to sea. They would prefer to sacrifice everything else rather than endure the emotional turmoil associated with that risk. This sentiment highlights a deep concern for the individual's well-being and a profound fear of loss related to their actions.