How can I pronounce the word remember and room correctly?

Since I was 19 I started having trouble saying the word "remember" and "room". I used to say these words fine and now it's hard to pronounce them. Instead of saying remember I sometimes say "rember" and instead of saying room I say "rooooom" (like really long). Sometimes I say remember normal but I have to concentrate really well to say it right. Why is this? I'm only 20 yrs old. Also sometimes when I talk the right side of my mouth turns more to the side (that started happening since I was like 18 yrs old). Did I damage a nerve or something? Can cracking your neck and back a lot damage a nerve??