Maybe they haven't let go of you.
In my way spirit/souls or what have ya don't just pop off as soon as they are released from their present physical selves, they can hang about for a time or forever if they choose.
You are not going bonkers in my personal opinion. Look at it as a gift as they stop by to say good-bye.
Death is a part of life, take it the way you want it.
First I would ask how old you are ... then I would say that you are a very sensitive person and you take friendship very seriously. My wife has been seeing the dead for as long as I have known her, 50 years, and they are always friends or relatives. She will tell me before we even get notified. Just take a deep breath and hold on because it may just be part of your Journey. Be kind and have a fruitful Journey. Mike
I get that life is part of death but even though that's true, it takes time to get used to not being in the presence of another. I feel you're lucky Baltazaar you get to see one last goodbye.