I'll be frank.
This has happened to us twice, and I can only describe it as being a living hell. It's that combination of hope and false leads that create such an emotional rollercoaster. I got so bad after losing our second one that my OH moved out of the bedroom we shared for over a month because he couldn't cope with me crying myself to sleep every night.
I understand why the not knowing is having such a dreadful effect, because your imagination will always try to fill in the blanks, which is far from helpful.
I didn't really cope well for a long time. I think it was about 6 months after he disappeared that a sort of numb acceptance took over and I stopped looking. We ended up on so many wild goose chases with well meaning people reporting sightings of cats which, when we eventually did get to see them, were nothing like the photo we'd posted of our missing boy. I appreciated the fact people took time to get in touch, but each time it was a negative was soul destroying.
Over the years I managed to shut down the painful memories and to recall the best of the times I shared with our two missing babies.
When I think of Suki now, it's as our sleek little black and white huntress - feisty and independent one minute, and snuggling up with my Mum, who she adored, the next.
When I think of Flynn, all I see is his uniquely "smiley" little face beaming up at me - he used to love to spend time with me in the garden, and would come down the lane to meet me from the bus when I would come home from work. He would pull the most astonishing faces, like the time I showed him a giant earwig and told him to be careful in case it ate him.
I know how very difficult it is, but I think each time your thoughts begin to wander into disastrous territory, you have to pull yourself up short, and replace the thought with one of a good memory of Ollie. It won't make things any less painful for now, but it will help to deter you from destroying yourself with "what-ifs."
I still hope that for you, Ollie will return home, but if it isn't to be, please know that there are many of us on Purrs who have stood where you are now, and who stand with you still, in friendship and with understanding.