Oh girl! I am so sorry but I think the advice you are receiving from these ladies is spot on. I am 49 years old and on my third marriage which I will have to say is finally wonderful. However, I had two marriages before and didnt take head of the warning signs. One ended with my husband being unfaithful and the other had a unhinged temper. I am here to tell you that you are better off to walk away from this one or at least for now. You are worth more than what He is giving to you. He will treat you no different with a wedding band on your finger. YOU are valuable just like the finest silks or a rare gem. A man needs to treat you as such. Never allow less!
I will also say, your finance’ may be lashing out to you because of your concern about his ADHD. It might be making him feel inferior or less than a man. Not that you are approaching him this way. BUT men like to feel like they are leading, respected and appreciated. Again, he may feel like this is an attack on those things. Men are funny creatures. Just food for thought.