I lost my friend…

8 days ago (10 September), my beloved and loyal friend passed away. He had lived a long and partially happy life for about 16 years. During the past six months, he had been fading away like a candle. I had moved to another city for my studies, and I couldn't take him with me due to rent difficulties. Every time I returned home, I witnessed his decline. Gray hair, mouth surgery, leg aches, deafness, blindness, then strange sores appeared all over his body, growing and bleeding. Despite this, he always tried to make me happy, and I remember that this last summer, when I gave him commands on a sunny day, and despite the pain in his bones, he tried to follow them. I felt sorry for him and gave him all the treats for free, and he licked my hand when I was crying alone and kept me warm during winter nights. Unfortunately, and in the end old age and cancer took his life. He died alone, at night. We were on vacation with my family for one month. And when we gone after a week he got really sick. Our grandmother looked after him, but she only came in the morning. I don't know if I'll ever forgive myself for this. Will the pain leave me? Will I find the strength to move forward? Because, of the deafness and teeth loss he was so afraid of the dark and loneliness during his last year, just like I was... I also remember that about 8 years ago, he started to go gray, and from that moment I was very afraid of losing him and being alone. Instead of enjoying life with him, I often felt nervous or cried. I regret it so much, because time cannot be reversed... I was such a fool... We could have done so many things together if it weren't for my fears. I remember when I took my bag and looked at last at him, he flashed in the doorway, then my mom said that we are going to be late on plane, and I had no idea that this would be the last time I would see him. And now, with the last warm summer rays at sunset, he's gone. I hope that maybe not in this life, but in the next one, we'll meet again! He gave me the most vivid and warm memories. Thank you, Jack, rest in peace, little one! (Sorry if I done any mistakes, I’m not a native English speaker)

Can you tell me, how to survive the loss of a pet? And to find the meaning of life and to truly become happy again? For me now it is more harder, and I was living with depression for 5 years.