I don't think you should abandon poetry. Even if you just write it for yourself. Art is expression, so if it is your passion, go for it.
I haven't kept up with the writing industry, but it might be easier to submit short stories to magazines first. I only know The New Yorker, but I'm sure there are many others that publish short stories. Once you get one or two published there, it might be easier to shop a short story book.
Also, if you do have trouble writing long narratives, short stories may be better for you.