Mystik Mama
Okay, questions first. Do you know what kind of sage it is, and what do the bugs look like?
For now, look at these guides:
Ehow.com's Sage Pest Guide
Growing Sage from About.com
Unless you live in an extremely dry area (meaning not just hot, but with very low humidity too) you may not need to water your plant every day. If the dead/dying leaves are yellow and wilty, it's likely that it's getting too much water. A good test for this is before you water it, stick your finger down in the dirt a little over an inch and if the soil still has moisture to it, it doesn't need to be watered yet.
On the flip side, if the dirt is too hard and compacted to stick your finger into, it's likely the water can't get down into the dirt and to the roots.
Also, does the plant get full sun? (8+ hours of direct sun per day). Sage needs tons of sun, but if it's too hot you might put a small shade over it during the hottest hours of the day (generally 12pm-2pm).
Hope some of this helps! I probably am watering it to much. I'll stick to watering it ever other day. My plant is under neath a flower tree, it gets the morning sun, and the evening sun (in SC that still bright and hot) during the highest part, the tree helps shade it some.
The bugs, I can't really describe them well because they are that tiny. They are about this size ( -- ) , white, they mostly stay in the dirt. I never see them on the plant. I don't know if they can jump, I never seen them do so. They crawl. (And they don't like water, but I suspect most bugs don't like drowning)
The summer heat I think is what did it. We get temps of over 104 and I think it might have dried out the plant and I think the soil needs changing. It's still a bit soft but it's getting nasty. It looks like the plant couldn't suck a bit of nutrience out of that dirt.