From what you describe there would seem to be a problem with your PS
and/or screen calibration.
By default, when you open an image in PS
it will use the default ICC profile (maybe supplied with you monitor, maybe one you've created by calibrating your monitor).
Proofing is meant for use to simulate how an image will look when sent to a particular device type.
Monitor RGB essentially ignores your ICC profile - ie. any calibration settings which might have been applied. The fact that you are seeing a yellow cast when not proofing for monitor RGB therefore suggests that your profile may be introducing the cast.
But that's just one aspect of the problem. Colour management is a real PITA. Going back to basics, first of all I would ensure that you are using sRGB throughout you work flow - camera should output as sRGB and PS
should be set to sRGB ...
EDIT -> COLOR SETTINGS then select sRGB as the RGB working space.
Also, under "color management policies" I use "convert to working RGB" which avoids unpleasent surprises.
By using sRGB throughout you should get reasonable consistency across browsers (which also work on sRGB - more or less), though you may still have issues if the browser is capable of using your custom monitor profile (which I suspect may be wrong).
To try and sum up, you need to address both the color space you are using and the way that space is interpreted (your monitor profile).
Some people advocate using AdobeRGB, and this is in fact the default working space for Photoshop (I think), because it has a wider colour gamut. But this is only of value if outputting to a device which can handle the color range. Standard monitors can't, and nor can web browser (AFAIK). Printing is of course a whole other issue, but sRGB works well with most online services (like Photobox). Printing for magazines and the like may need to be converted to CYMK, but I wouldn't worry about that as the people doing the printing are skilled at doing the necessary color space conversions.
I've tried to keep this as brief as possible, so apologies for omissions or oversimplifications - entire books have been written on the subject!!
BTW - you may have at some point correctly set up PS
color settings, but I've noticed it can sometimes forget these, particularly if PS
shuts down abnormally, so worth checking everything is as it should be.