It takes time to get better at chess. If you've only been here a year 1200 is not at all a low rating IMO.
You may have worked tactics so much it's your strong point now. Time to exercise something else. Learn some strategy or endgame, post games to analysis forum, stuff like that. Targeting the weakest link gets the most results.
I think it's also important to try longer games to give yourself a chance to apply new knowledge. Blitz only gives you the time to play what you know instantly. At some point we all hit walls and have to wait for improvement to kick in again. This is more so if all you do is play blitz (I would know, being a former blitz junkie).
I still get crushed in the 1200 bracket, I feel like I'm just wasting my time. I can't deny it's nice to have learned those patterns but it seems those kind of positions are never reached in my games, don't know how to make it happen, it's never as obvious as in the puzzles. I only feel frustration from all this, I'm not improving at all.