Junior year of high school was particularly bad for whatever reason. There was a lot going on in my life at the time I suppose. Aside from that, middle school was pretty darn rough. Overall though it has improved with age purely based on practice & adaptation. I know it sounds rough, but the more you talk the more practice you'll get. BUT, if you start to feel actual pain from blocks, stop your sentence. The pain and residual twitches that can manifest are not good. I did damage to my jaw many years ago trying to force out of blocks. Be patient with yourself, and don't let others rush your speech or tell you to "spit it out". They either have to be patient with you, or they can screw off.