Putting a high ammount of your energy into something may result in something alike. Don't overwork yourself, always do spellwork with a high concentration and visualization and always after relaxing and maybe cleansing yourself. Your spellwork and your energy must work together as one in a certain way, and if anything is troubling your mind while on the proccess it can result in failure or backfiring.
But of course, not everything happening with you may be caused solely by magic or spells. It could be something of your body or mind. If you are feeling depressed or if you have any physical or mental troubles before or after a spell or anything in general, you should look forward to talking to someone about it, a parent or a professional. Your health is very important no matter what and manteining it would certainly help you live better and even help with your spellwork.
I used to have the same problem when I was first learning about healing and energy working. Any time I did a healing session with someone I would feel weak and tired after, Like I was drained out and just wanted to sleep it off. For the first while i thought it was just because I needed to practice more, and the feeling would go away as I got better at it or more practiced. But it kept being the same every time.
Finally I was talking with my great-aunt Bette, who was the one who had introduced me to energy working, and asked her about it. Every time she worked energy it seemed to invigorate her, and she could do workings for an hour or two and not be even slightly fazed. Her answer was a simple one.
"Why are you using your own energy?"
It was so matter of fact, simple, and obvious it took me by complete surprise. Your personal energy is self-replenishing, it can rebuild itself through nutrition, meditation, sleep, and that sort of thing. But it is still your personal energy and sending it away, especially en masse, is something to be avoided. The idea is to build up your energy, not drain it away. So instead of pushing around your energy when working energy or magic, channel the energy through yourself from elsewhere. Whenever visualizing the flow of energy through yourself, imagine it coming in from your crown (the top of your head) or up through your feet from the earth, then through yourself and projected outwards as guided by your intent.
Don't be the pond trying to feed the desert. Be the pipe that connects to the ocean instead. ^_^
