Try to remember that your partner might need more explanation for your thought process than you think is necessary, especially if it’s a “negative” thought.
“I disagree with you” –> “I disagree with you, but I’m not angry at you, and I’m not going to yell at you for not agreeing with me.”
“I’m hurt by what you did” –> “I’m hurt by what you did, but I don’t hate you, and I don’t think you’re a bad person. I just want to discuss it.”
“I’m frustrated” –> “I’m frustrated, but it doesn’t mean I don’t care about you.”
What feels obvious to you–the underlying asumption that of course you still love this person, of course this is just a single feeling–is not obvious to someone who has been trained to flinch at every criticism. Take the time to explain your feelings and their meanings to ease both your fears.