Just an alternative suggestion here...
What about arranging for a coffee with the guy that is giving you the grief? You could then, informally, test the waters about how he is experiencing things - from the horses mouth - NOT via your line manager. You may also be able to share some of your concerns with him, that face to face and relaxed, he may be more willing to take on board, rather than the official route.
It sounds like your confidence is taking a knock at the mo, and if you tell him you need a bit of a pep talk about the projects you are on, ask him for an overview of how he perceives the progress, you may be able to build up a better rapport, which would enable you to address the issues that are concerning you in a more constructive way. Getting HR involved could be a real snub and get his back right up, which could put you in the firing line for lots of other stuff.
You never know (not defending, just looking at it from the outside) this guy may be under tons of pressure, be hating every minute of his job and actually struggling himself.
I have recently been advising a friend on a similar situation at a place where we both used to work (so I know everyone). She was paranoid that she was being victimised by her line manager and her line maanagers boss. To the point that every reaction to even a basic enquiry from either of them was "OK so what have I done wrong now - when do you sack me". SHe was totally wrong, things weren't perfect, but they wanted her to succeed - if she didn't then it meant they didn't as well. SHe is over it now, still a bit cautious in some areas where she is still developing her skills, but realises that she was so defensive that even when help was offered she wouldn't take it for fear of being seen as weak.
By having a chat with her boss and line manager and explaining all this (took me a while to convince her...) she is now much much happier.
Just a thought, keep your chin up. HTH