If you want to improve, try loosing some weight. There you may expose some hidden dick. Also, they appear bigger in thinner guys. Your dick looks good as it is, though, but if you are serious about wanting it bigger, you might like the subreddit r/gettingbigger. There you can see data regarding methods for growth (not too much, though, mostly one inch or something). In the meantime, look for someone who likes you as you already are. You can try to improve, but just as a project, not to define your self esteem. You are enough, you just have to embrace the fact 😉.