Not good at showing emotions

I don’t really show emotions/express how I feel to others. I don’t really flirt/give compliments because I’m not good in that department haha. (Besides saying something along the lines of you’re cute/handsome, you have a pretty smile). I also don’t really let people in...it’s just how I am. How do I go about showing/saying my emotions and how I feel and letting people know I appreciate them and are grateful to have them in my life besides telling them? I’m also not the type to take lead and (for example) kiss my boyfriend or be all up on him.

I’m just upset because people think I’m pushing them away and say it’s like a brick wall lmao. They want to try and get past this “wall” that I have up... I’ve never been the type to just let people in/tell them everything. Nor have I been the type to say how I feel..advice? Anyone else the same way?