Urh! I've had an experience with this type of guy too and you're spot on.
I broke things off with a guy I was seeing years ago, lots of reasons why but what stuck out the most was how clingy and emotionally manipulative he was. When I spoke to him to break things off (after 5 weeks of dating) he drew the conversation out over hours and hours challenging everything I said (I was trying to be polite with him and put it down to 'me stuff' to try and spare his feelings - at the time i was thinking maybe we are just not compatible and the things I find creepy and OTT might be endearing to someone else)
After literally the 50th round of tears and him shaking his head at me and muttering "nice guys finish last" I really wanted to scream at him MAYBE YOURE NOT AS NICE AS YOU LIKE TO THINK YOU ARE but I still felt a bit mean. A few months later I heard he had been dating a friend of a friend and I was really excited thinking maybe they were well suited but no he pulled the exact same bullshit on her including the 3 hour long exit interview where he actually asked her how she could live with herself doing this to such a nice guy
Self proclaimed nice guys are the worst