May I wish you a warm welcome to the CameraLabs forum.
I was in a similar place back in 2012 with my Canon 5D MkII. I had a good selection of "L" lenses but size and weight meant that increasingly that kit got left at home.
From my Signature below you can see my own solution, one I arrived at pretty much because of the excellent range of lenses available. I didn't need the ultra-shallow depth of field that my Canon kit offered and I'm relaxed about the continuous AF limitations of most mirrorless cameras. IQ is plenty good enough for my needs and best of all the E-M1 plus the 14-42 "body cap" fits in one, admittedly capacious, pocket while the 12-40 and 7-14 lenses fill another similar pocket. The result is that instead of sitting at home gathering dust my camera kit is now always with me gathering pocket fluff.
My solution may not be right for you but there are other mirrorless options out there. You can even stay "full-frame" with the new Sony A7/A7r but I'll sound one note of caution and that is that while the bodies of the new breed of Compact System Cameras may be small if you want low light performance or shallow depth of field then the lenses can't be similarly shrunk. Indeed they may even not be available or very expensive. For example a full-frame f/2 equivalent on m4/3rds would need to be f/1 for the same depth of field and there are precious few of those about!