Is it permissible for me to speak with my female colleague as colleagues, while observing the limits of Islam, and offer her assistance if she needs me, after I decided to distance myself from her because I know that love without marriage is forbidden?

Love that leads to declaration and communication between a young man and a young woman before marriage is forbidden. The duty is to repent from it and sever the relationship immediately. What is mentioned about the difficulty of this matter is nothing but a whisper from Satan to maintain communication. It is not permissible to speak with a young non-mahram woman except out of necessity, while observing the Shariah controls. The scholars have mentioned ways to cure infatuation, and whoever is sincere with Allah, Allah will facilitate the cure for him.