Yes, it is correct to say, “this is the reason why I have trust issues.” However, you can also rephrase it in different ways for variety or clarity. Here are a few alternatives:
1. “This is why I have trust issues.”
2. “This explains my trust issues.”
3. “This is the reason I struggle with trust.”
4. “This is the cause of my trust issues.”
5. “This leads to my trust issues.”
Feel free to choose the one that fits your