you if you've never had a LTR? Women want the man to have had a LTR. But to have had a LTR, you would have had to have had a LTR prior to that. It seems like once you've been alone for too long, you're trapped.
Who says women only want men who have been in an LTR? If you know why you haven't been in one - professional or educational priorities, haven't met the right person, chronic shyness - explain that to her. If you don't know why you should figure that out before trying to jump into one. A lot of long-term relationships just happen organically. Relaxing about the entire issue may be the best way to make one happen.