have not been producing at the plate?

I am High School Senior and I have been playing Varsity since Freshman year. I have been having kind of a slow start this year and its frustrating to be honest. I have power...tons of it but whats the point if I'm not making consistent contact. I spend my Saturday's hitting off a Tee at the park by myself, while doing so I hit as if I were lifting weights...by breaking it down into reps/swings per set. I do middle, outside, inside, low etc. Long story short I take a little over 350 swings not including the reps I take at the school batting cage. I do everything I can, I take the extra bp, I look at video's, how I bat and yet whenever I step on the plate I either hit the ball really hard or strikeout. Like today I went 0-4 and in my first AB I hit an MLB pop up I'm talking about I was on 2nd when it dropped. In my 2nd AB I hit a hard groundout and when I asked my friend on the team "what I'm doing wrong?" He said "nothing... you're hitting the ball fine" then I struck out in my last two AB which is when I got frustrated and had to take a little walk by myself to cool down. Please help me out I really want to improve my hand eye coordination because just like my coach said "you have power you just got to make contact" plus I'm going to a D2 College next year and I want to be somewhat prepared. Thanks for reading this and I appreciate any advice or tipps given...thanks again