Okay @landonb08, what is your plan? You've shared what your coach said, and he sounds like a lot of high school coaches I've known over the years. He's challenging you and he's probably challenging others on the team to compete for playing time. That is what he is supposed to do to motivate you to get better. What are you going to do to prove him wrong? As my youngest son's hs coach used to say all the time...."figure it out".
If you've spent any time on HSBaseballWeb there are many, many stories of guys who find a way and refuse to succumb to what others think. My oldest played on a stud national team back in the day, and all the players were recruited from top D1 schools in the area. My son's teammate was a smallish kid, and the last to be recruited from this travel team and he was kind of an afterthought at best. Years later, he led his D1 school in homeruns and was drafted junior year. Before he got drafted, he and my son were the only two left playing college baseball from this elite national travel team. They were both the last to be recruited from that travel team. You've got to believe in yourself, work hard, and find a way to get on that field. Attitude is everything in life, and this is no different.
JMO, and Good luck!