You have gotten some great insightful feedback from.some wise people.I agree with them.
Another way to look at it could be that H is unable to openly discuss his thoughts. It is not only easier to do so in text but maybe the only way he is capable of communicating "openly".
In the past I have expressed my sentiments to my W in written format. I wasn't capable to formulate my thoughts as good in front of her. It would have been preferable and much better to openly discuss stuff, but at the time I was depressed and even without the depression it is not natural to me. Maybe he is a coward but chances are he cannot contemplate doing it otherwise.
I am not saying this for you to let it slide. I believe good boundaries are important.I say this so you feel less negative towards him and his texts. And hopefully they will not affect you then.
Best wishes
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together