You know, I hate to give advice because my life has been so odd that almost nothing that’s happened to me can apply.
But if you really love to write and you really love to tell stories and you really love to draw, you just have to keep doing it no matter what anybody says. I sent my stories off to publishers for five years and got a good jillion rejection slips — and for all these different reasons: “you can’t do books about boogers,” “you can’t do books about dinosaurs,” “you can’t do books about this.” And you know, it all turned out to be wrong.
If you really want to tell stories, do it and don’t be dissuaded.