Here are some quotes on relationship problems that I found:

- "Relationships are complex. outcomes are uncertain. People are irrational." — Hugh Mackay.
- "When someone is hard on you, it may have very little to do with you." — Bryan McGill.
- "In general, the problem in a relationship is when the couple stagnates." — Simon Baker.
- "Assumptions are the termites of relationship." — Henry Winkler.
- "Love can sometimes be magic. But magic can sometimes just be an illusion." — Javan.
- "Hidden resentments poison a relationship; so if something bothers you, say it." — Joe Navarro.
- "The ultimate test of a relationship is to disagree but to hold hands." — Alexandra Penney.

I hope these quotes help you in some way. Let me know if there's anything else I can help you with.