well, you just started boxing. It takes time to get power with some strikes compared to others even after being shown the proper technique. I didnt just start throwing great front kicks from day one and I'm sure that applies to hooks aswell. Also, just because a strike doesnt feel strong, you really don't know how effective it will be till you use it in sparring. With the right angle and placement a horizontal hook could work for you and would give your sparring partner different looks.
No, I did not start boxing just now. My TKD instructor taught boxing against mitts, not kata techniques, as most TKD instructors do these days. If I haven't gotten comfortable with it against hard targets in the past 3 years, I doubt the next 3 will be any better. All I need is to lower my elbow to a vertical one and I can blast away.