Trouble maintaining skill

[Pizza69]

So I've been around for a bit and pretty much hit my peak at around D6.6 or 6.7 or so probably around November 2015, and since then I've mostly just been treading water. Which isn't to say I haven't been getting some decent scores - there have definitely been some more recent scores that I'm proud of, but since then my overall level of skill has been very slowly but steadily going down, and I'm not entirely sure why. I haven't changed my playstyle or setup, and I've always been trying to push myself (within reason) where possible, but I can feel myself losing skill and it's discouraging. About a month ago I decided I'd take a short break and see if clearing my mind would help. Unfortunately it only exacerbated the problem, and now I'm noticing on top of mental walls that I just can't seem to get my hands in a comfortable position, and despite everything I've tried the best position is still the one that I've used for over a year now. This is making it basically impossible to enjoy playing for the fun of improvement, does anyone have any advice/things to try out?