Premiere Pro crashing, error in effect controls panel, error in preview

Hello! I need help, please. My Premiere is slow, freezing a lot at times, and even editing CC is difficult at times.
 I need guidance to solve this problem. The preview is giving an error; when editing subtitles through the preview 
panel, the software responds as if I had the timeline panel selected and keeps activating the tools with shortcut keys. 
In the effect controls panel, I sometimes can't control the position's speed curve as needed; the software doesn't 
allow it, and I'm unable to animate correctly. Please help me.