A little help.

I'm not an emotional person, I never have been .... I don't express my feelings and I'm pretty heartless . I don't know why, I've just always been that way . I I'm not a lovey dovey person either, like I don't like to be kissed on & loved on, and touched all the time. like I actually get mad. i promise, I'm not mean. I just don't care about things I should. Anyways, my husband sends me like paragraph long texts every morning and literally expressed his love and appreciation for me on a daily basis and I never say anything back . not because I don't love him, just because I don't know what to say back . I'm really bad at it, he doesn't really say anything about it but I know it bothers him that I don't express my feelings and I'm not lovey dovey in any way, but I want to make him happy cos he deserves it! Any advice on how to be more caring and loving?