I don't know why you have chosen ruining yourself with drugs over the life you used to happily lead. Without a conversation with you, you leave me guessing. I have met people in your situation who decide that there is no going back. Such is just another lie from Satan. Usually this passage is dangled in front of the deceived:
"For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come, if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame" (Hebrews 6:4-6).
Satan whispers in your ear, "See, God has rejected you. He doesn't want you back." But it is a twisting of what this verse says.
Who is this verse written about? It is talking about people, like yourself, who once had salvation but decided to throw it away for cheap, temporary, worldly thrills.
Who is this verse written to? Is it written to the person who fell away or to those who try to bring them back? Read it carefully. It is written to people, like myself, who long for your return. God is telling me that I can't make you come back. I have little to offer you that you don't already know. I can remind you of the truth you already know, but I can't tell you something new that will suddenly make you realize to the depth of your soul that you need to return. It is impossible for me to bring you renewal.
"There is nothing final about a mistake, except its being taken as final." (Phyllis Bottome, 1884-1963).
The hard truth that I have to face is that there is little I can do until you want to come back. All I can do is wait, knowing that each passing day sees you increasingly damaging yourself and digging a bigger hole to climb out of. I want you back. I'm committed to wait and reach for you as long as the good Lord allows me. I fear at times I have years of tears in front of me. But if that is my lot, know that I think you are worth it. I won't give up on you.