In life, we go through some pretty tough things as individuals that effect the way we are in relationships with others. Those things from the past that are unresolved within ourselves can grow into a larger problem. If your issue is trust, for example, that issue can prevent you from trusting yourself and trusting others. If the person that you're with has done nothing to make you feel like you can't trust them, your past trust issues can be seen as unfair. Your current partner can help you work on that issue, but at the end of the day, our individual issues are as said, individual issues. As individuals, we must not wait to resolve issues from the past. With you working on yourself, sometimes your partner will not totally understand what you are going through. That's okay, but don't be too upset at them because it's not really for them to understand. It's up to them to support you in your journey to becoming a better version of yourself. Becoming better helps you, as well as the relationship in many ways. Unresolved issues effect relationships daily. Make sure if you have those, communicate and work towards a solution.