I also have a similar concern, since I am the same height as you. To make it worse, I am around 175 right now.
First off, I am not super technical just yet, I am more of a ground person, so striking is new to me. I was sparring my brother(without instructor) and he is like 5'8" but he weighs like 155. I was getting owned; every time he would jab, I would get hit if I didnt dodge, and every time I would swing I would miss him. And if I did duck his jab, and threw my own, he would just throw another jab and hit me(prob due to his speed being lighter).
My strategy against him was to clinch up and throw hooks to the liver which had him down pretty quickly. Sadly, this only worked against him, I am sure a more experienced fighter would be able to defend that.