His refusal to understand you is a red flag. Saying “I dont want to talk to you like you’re stupid” You’re stupid is a red flag. Also, you should try to understand and DO NOT CONVINCE. I repeat, do not convince him of anything you think is right. Its like arguing with parents and you will not win. He said you are gaslighting him but ask him for examples then proceed with “how does that make you feel?” And then “what are some necessary steps we can make as a couple to be on the right track?” And then something like “what are you assumptions about how I am feeling?” “What do you think I am thinking about this situation?” Pretty much ask questions that ENHANCES communication between both of you since communication is key to a relationship. I highly recommend you check out Dr.K on youtube. A lot of good stuff to watch and teaches you new perspectives