How do I tell my girlfriend who I have date for four years that I don't want to be with her anymore?

It's important to approach the conversation with honesty and compassion. Choose a private setting where you can talk openly, and express your feelings clearly but gently, emphasizing that this decision is about your personal needs and growth. Be prepared for her reaction, and listen to her feelings as well. Ending a long-term relationship is difficult, but being respectful and clear can help both of you move forward.