I can last 15 mins using condom. but if i don't use it, i find myself ejaculating in 10 seconds. is it premature ejaculation ?

If it occurs sooner than desired, then technically yes, this would qualify. There's nothing wrong with using a condom (actually many good reasons to do so), unless your'e trying to have a child. I wouldn't "worry" too much about it as anxiety issues, often related, has a tendency to feed off of "worry". If it bother's you enough, speak with a trained therapist. Solutions exist that can help.

yes . Stay with the condom