Motivation...or lack there of

I cannot seem to get any motivation to get back on an exercise regime. I start a dvd and then stop after about 5 or 10 miinutes. It's not like the dvds are bad. I just can't stick with it. It could be because I still can't afford a gym membership yet and that has me a little bummed. I need to do something before my clothes really start to not fit me.