Relationship Advice

I've been dating this guy for about two months. We were best friends for a year before we started dating. We fight quite a bit, about different things. It's been a rollercoaster two months involving everything from the death of family members to sports scandals and career ending injuries. I've had some problems and I tell him a lot that it's difficult to put my whole heart to him when I'm so afraid of getting hurt after it all. He says he loves me and that he understands he's very kind and we both have love and respect for each other but we have complicated disagreements sometimes. How do you know when the fighting becomes too much and what to say when you're not sure how to feel. 

Thank you for your help❤️