Determination is the will to acheive a goal. There are many ways to motivate yourself through inspiration and philosophy. If you want to improve your mood, which is often a reason for lack of motivation, I can recommend you two herbal supplements that I have tried and both are my favorites.
Dragon Herbs Will Power
Dragon Herbs Schizandra 500 mg
1 or 2 capsules of the above product a day will be enough to feel your mood heighten. I take 1, sometimes 2.
You can find these in iherb.com - copy and paste the title of the product in the search box there. Use this discount code at check out - DOB496 - for 5$ OFF + free samples. You can also get free shipping if you live in USA and your order is above 40$.