I am sorry to say that in 30 years in aviation, whilst they may not all have been very close, I have lost rather more friends and colleagues than that as well as professionally having participating in the investigations into accidents to strangers.
I can't honestly say that I have ever got over any of those deaths. I am regularly reminded of them, and their lives and the loss caused by their deaths are always with me. Very much as DAR said, I have let the loss guide me in my aviation existence, both private and professional - it has often guided what I've done, in particular support to aviation safety research, and thinking hard about multiple aspects of my own flying.
You never get over it, nor should you try. Commemorate the loss by letting it help you become a better person, and a better aviator. You will not enjoy the journey, but I think it's the only way.
G