I can't masturbate because I can't get wet when I'm by myself !

So I try to enjoy myself and masturbate but for whatever reason I CANNOT GET WET ON MY OWN. In person with my SO I get extremely wet in a matter of seconds and the sex is fantastic. But whenever I'm alone I can never get myself horny or wet 😭😭😭 does anyone have ideas why this is happening or what helps???