Rebuilding is totally doable. It takes some practice and research, certainly. The rebuildable coils section of the board might be a way to get a bit more information on the topic. This is also an area where you tube videos really help... IDK the solution to going through coils that fast, though my coil life isn't great as I have gunking factors, I am able to vape them far longer (lately) than I have been. I have to avoid extra-sweet or dark storebought juices, but since starting DIY that problem has really gone away.... My coils are happier with less sweet, less flavored juice, and while I still enjoy my flavors, they are on the lighter side. It took some tinkering, but I find DIY far easier than coilbuilding. I also wash and rinse my BVC Nautilus coils and reuse them once, to minimize costs. The second go round, they do go bad faster, but they're good for 3-4 days, which isn't bad to extend coil life. I do try to take them out just BEFORE the juice starts tasting awful, but I'm not always successful and it seems to work anyway. I let them sit in hot water then soak for 12 hrs, clean rinse and dry outside to get all the moisture out.
Final point, I find that continuing to inhale after I stop hitting the fire button seems to wick juice up as I go, kind of repriming as it were. Since they're small coils, this seems to help. I really haven't experienced many dry hits vaping in this manner. May also help with the "wait 40 seconds til next drag" issue.
Good luck!
Anna