Feels like a bad Girlfriend...

My boyfriend and I have been together for 2 years. And he is very affectionate. He is always hugging kissing cuddly I'm just not into it I like my own space. Last night he told me it hurts his feelings that I'm not lovey dovey he said he gets jealous of guys that their gfs are all over them. I don't want to hurt my boyfriend but how do I get myself to be someone I'm not?