I've done loads of huffing in my past, what do I do?

It's been about six months since I've huffed. Huffing was the most blatantly ridiculous thing I've ever done in my life, and I'm proud to admit that at only fourteen. Lately, I've been taking into account that I can't remember certain things, and some incapabilities of concentration. I'm assuming it's from the long term effects of huffing, possibly? Please respond with a solid educated answer. Thanks for the responses