Hey, Mike;
Things I have learned the hard way:
(& you may want to re-read this in ~ 2 wks, & again in ~ 2mo).
I can relate to how you're feeling; I said goodbye to my cat Shadow in late '03. That hurt like hell for 6+months.
The amount of pain we go though from a loss (separation), is directly proportional to the love/bond that was broken. Interestingly, if I dwell on that moment, I can recreate the pain & depression that followed, but when I focus & dwell on the good memories, I can recreate the good & comforting feeling(s) I had when Shadow was alive. Grieving for a pet is at least as important as for any other loved one, ( I say this, because a pets' affection is given freely, unlike a lot of humans, (unfortunately), as the loss is very real. Take the time you need, to do it when & as you need. There is no mechanical process, nor time line, although there are some helpful pamphlets for this. This is important: the pain will subside, but by acknowledging, accepting & then letting go of the pain (of the loss), you in *no* way are letting go of the memory of kitty. In fact, you will find that it's easier to remember the good times & things with & about kitty.

.
For what it's worth: It sounds like you were *extremely* close to kitty, so this may be difficult to replicate, (the tighter the emotional bond, the harder it is to do) but it's worth trying. If it doesn't work at 1st, *don't* force it, just let it flow. It is: notice (when you're not thinking about kitty), from just near the outside edge of your vision, you will see momentary movements/shadows. You may see a partial image (like a quick flash) of kitty, usually near her favorite spots, or walking areas. When you try to focus on the image, it'll disappear, so try to resist moving your attention to that image. Just mentally take notice, smile, & say "Hi kitty (her name), thanks for dropping by". It is, quite literally, her spirit, that you catch a glimpse of (still concerned about you & not yet ready to leave this plane). Also, when going to bed at night, sit quietly on the edge of the bed, clear your mind of thoughts & noise for a minute or so, think nicely about kitty, & then speaking quietly, ask kitty to come to you in your dreams & visit, or, that you would welcome a visit in your dreams. Most likely, it'll happen just after you fall asleep (maybe), or (probably) just before you wake up in the morning, in that not-asleep-but-not-awake time.
I have had these things happen to me from at least 3 pets. The best was; Shadow visited one night, & walked across my stomach, carefully, all ~ 13lbs of him, then curled up next to me - after he dropped against me hard, & purred loudly. I could feel his weight, soft fur, & his physical bulk, & hear the purrs. When I woke up too much, he was gone. He had died in my arms 3->4 months earlier.
If you can, find a quiet spot in the sunshine for a few minutes or so(maybe a half hour, if you can?), & sit there w/a pic or two of kitty, & find some peace. It'll be there.
FWIW: When you cross over, kitty will be there to welcome you, if you want.

.
HTH.
Peace.
Marcus...