Boobs and sex in general

Hey ladies! When a guy plays with my boobs I never feel it and get super turned on. I heard that girls can orgasm just by a guy playing with their nipples. Is that true or just a myth? I want to enjoy it more but I just don't get the tingling feeling like I do when I go solo. Could it be that I'm not relaxed or into it? I wanna make sex more fun for me and I just feel like k do it wrong. I've only done it four times and only two out of the four was actually fun for me. I'm such an amateur!