All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all we have to tell you that you should take it easy and you should not burden yourself with something that you could not bear. Besides, you should not let the devil overcome you. The depression that you are experiencing is probably because of the whispers of the devil who is trying to spoil your religion and your life. So you have to be careful and you should know that there is a solution to every problem. The solution for this is in seeking Allaah's Help, invoking Him earnestly, and asking Him for guidance at all times, as He is the one who grants guidance and enables people towards it. Allaah says (which means): {...but Allaah guides whom He wills. And He knows best those who are the guided.}[28:56]. So, if you sincerely seek Allaah's Guidance, Allaah will bless you with it.
Additionally, we advise you to find out the reasons that prevent you from being steadfast on Allaah's Religion. You are probably more aware [than ourselves] about them; the reason might be that you are living in a corrupt environment or that you are befriending bad company. It is most likely that a Muslim who is living in a non-Muslim country finds himself in a corrupt environment that affects him/her in a bad way, or is harmed by the bad company. The scholars stated that it is not permissible for a Muslim to stay and reside in a non-Muslim country if he fears to be afflicted in his religion. So, if you are from a Muslim country and there is no necessity for you to stay in that non-Muslim country, it is an obligation for you to return to your country if this is possible. If we assume that there is a necessity for you to remain in that country, you have to stay away from anything that might hinder you from following the right path. You have to hold fast to anything that might help you in performing good deeds and acts of obedience to Allaah, like keeping company with righteous women or girls, and attending circles of the mention of Allaah like lectures and the like.
Finally, we like to draw your attention to the following matters:
1) You have to repel the whispers that come to you and do not take them into consideration, especially if they are about belief. You have to be careful not to let these whispers overcome your heart or lead you to utter or do anything that might cause the Anger of Allaah.
2) Abandoning prayers is very serious, so you have to be careful and you should constantly perform them. Some scholars consider that whoever abandons prayers out of laziness is out of the fold of Islam.
3) Committing suicide is a great major sin. The Prophet severely threatened us about it as he said: "Whoever throws himself from the top of a mountain killing himself, he will be thrown in Hellfire tumbling in it forever, and whoever drinks some poison and is killed, his poison will remain in his hand and he shall keep on drinking it in Hellfire where he will stay forever. And whoever kills himself with an iron (made material) his iron will remain in his hand and he shall keep on stabbing himself in the Hellfire, where he will stay forever." [Al-Bukhari and Muslim] So, resorting to such a crime, is like fleeing from heat into Hellfire.
4) Fornication is forbidden, and all means that lead to it, like kissing and the like are also forbidden. So, you have to be very careful not to commit what leads to fornication, as they are means that ultimately lead to it.
5) You have to advise your aunt as much as possible, and be keen on facilitating to her the means of guidance even indirectly by letting her listen to some beneficial (and influential) lectures in tapes.
6) We advise you to seek Allaah's pleasure even if that might anger people. The Prophet said: "Whoever seeks Allaah's pleasure by angering people, Allaah will suffice him from the people, and whoever seeks people's contentment by angering Allaah, Allaah will forsake him and leave his matters for the people." [At-Tirmithi]
Finally, we draw your attention to something that you have mentioned in your question. This matter could be more serious and more sinful than what you imagine, which is the thing that you mentioned that you were doing for the last ten years. You have to get rid of this matter to rectify your affairs as sins are disastrous especially the ones that are committed continuously for a long period of time. This is evidence of the lack of a religious deterrent and a submission of the person to the devil and his own desires which is inclined to evil. Among the things that would help you to get rid of this act is to endeavour to get married with a pious man who would satisfy your desires and help you to hold fast to your religion and bear the hardships of this life.
Allaah knows best.