What does my dream mean?

In my dream it was around 3 in the morning(but it was sunny and some shops worked xD) and I was with my boyfriend and a friend of his(a girl). So we went to look for an open shop to buy frozen pizzas. When we found one, we went somewhere( I think it was his place but I’m not really sure since I’ve seen only his bedroom) and we cooked them. After they were done eating they disappeared somewhere and I was alone in the kitchen. When I went looking for them I saw him doing her on the sofa. I was both angry and sad. After that I don’t really remember what happened…I think my parents came to take me home but I’m not really sure. Then the scene changed and… my boyfriend died( I can’t remember how though). I was crying like crazy and I could feel real tears in my eyes. Then at the funeral I just laid on the sofa(yes, there was a sofa xD) and cried my eyes out. Oh and my ex and his friends were at the funeral too but I didn’t even look at him. I would like to know what does the cheating and the dying part mean.