When someone says, "I'm so lost in you," they are expressing a deep emotional connection and attachment to you. It is an intense way of saying that they are completely absorbed or captivated by their feelings for you. The phrase implies that they feel strongly drawn to you, and you hold a significant place in their thoughts, emotions, and life.
It often indicates that they are infatuated or deeply in love with you. The person might feel overwhelmed by their emotions and find it challenging to focus on anything else because their thoughts and feelings are centered around you.
While the phrase can be romantic and flattering, it's essential to approach it with a level of caution. Intense emotions can sometimes cloud judgment, and it's crucial to ensure that the feelings are mutual and that the relationship is healthy and balanced. Communication and understanding between both parties are essential to navigate such strong emotions effectively.