Yes yes yes, Tony. I was struggling and groaning and crying for MONTHS when I first started because I just couldn't 'run' for more than five or six minutes at a time. I eventually got an HRM (£40 from um, dunno - an ad in RW, anyway. Blitz?).
I didn't think it was possible for a penguin such as I to go too fast, but obviously I was. To keep my heart rate down I had to slow down even further, and bingo! I waddled for 20 minutes without stopping.
I can't recommend one highly enough. Also buy the book 'Heart Monitor Training for the Compleat Idiot' by John L. Parker jnr. It will change your running life! :o)