Problem related to brain. Future harm?

For almost all my life, I've been studying really hard but haven't been able to perform academically. I often suffer from anxiety and depression almost everyday and even with maximum effort my academic performance is low. I have a hard time trying to concentrate in any form of work. I also get irritated and annoyed very easily. Before my exams, I studied for 10 hours a day and still couldn't cross 80% percentage. I also have sleep problems almost every night for the past 4-5 years. Sleep usually comes around 2-3AM everyday. I also never feel hungry. Depression and severe anxiety attacks are very common. Almost on a daily basis. Anger and irritation also. Is this a serious brain problem? Will it cause any future harm? P.S I have also recently started consuming marijuana.