Your dream is rich with symbolism that reflects your past relationship and the emotions tied to it. Here's a breakdown of some key elements:

1. Text from the Past: This suggests unresolved feelings. The urge to help indicates a desire to reconnect or support someone you care about, even if the relationship has become distant.
2. Legless Woman: The woman may symbolize parts of yourself or your past relationship that feel incomplete or hindered. Her lack of legs could represent feelings of vulnerability or being unable to move forward fully. The baby could signify new beginnings or the innocence of your early feelings for this person.
3. Transformation into a Cat: Cats often symbolize independence and mystery. This may reflect a transformation in your feelings or the dynamic of your relationship, suggesting that while you may have had strong emotions, there is also a sense of detachment or self-sufficiency now.
4. Driving Away: The act of driving away signifies a desire to escape from past pain or unresolved issues. Seeing the woman running after you could indicate that these unresolved feelings or memories are still pursuing you, even if you're trying to move forward.
5. Foggy and Rainy Environment: This could represent confusion or uncertainty about your feelings and the future of your relationship. The fog suggests that while you are trying to move on, there may still be a lack of clarity regarding your emotions and the nature of your connection.

Overall, your dream reflects a complex mix of emotions regarding your past relationship—feelings of nostalgia, unresolved tension, and a desire for closure. It may be beneficial to explore these emotions further, either through journaling or discussing them with someone you trust. This could help you understand what you truly want moving forward and how to navigate your relationship with this person in a healthier way.