Feeling guilty for being happy after a breakup is common, especially if you initiated the breakup or if your ex is struggling. You might feel like being happy means you didn't really love them or that you're being insensitive to their pain.
Remember that your happiness doesn't diminish their worth or invalidate what you shared. You're allowed to feel relief, joy, and excitement about your future. Healing and moving forward is healthy, not cruel. Your ex's healing is their responsibility, not yours.