Older cat acting strange

I have a female tortoiseshell cat. Her name is Patch and she is about 12 years old. She has always been a cuddle kitten and has always had some stiffness in joints (especially hips). Over the last few days she has gotten extremely clingy and has continually forced herself into the middle of any situation, more so than she has ever done in the past with out being visibly sick (which she is not). There was even one point where she almost jumped into the arms of my mom's boyfriend who was standing a good four feet away from where she was sitting on the top of a recliner. Shes also been begging for a good deal more food than normal. Other things that seem to have change have been her front leg seems to hurt her a lot and she rarely puts any weight on it at all. When gently feeling it to see how it is and then feeling her other paw it seems a good deal weaker too. We have had the vet check this leg out and he can find nothing wrong. She also has seemed a good deal different when I look at her when she is sleeping. She has taken up to sleeping curled around her scratching post and half laying on her face. I'm hoping that someone might have some information on what might be going on because I keep getting this feeling that she will be leaving me soon but doesnt really seem to have any major health issues to indicate this. Thank you for your help!

did you get blood work done? or any health test beside the arms? maybe she is having BAD arthritis and it doesn't sound good i don't know whats wrong with her since him not a vet.

my 13yr old cat <2 wks from her bday she was acting pretty badly in health and my vet said she was fine <bad vet< i switched her to 11+ wet and dry after a month i seen her play for the first time in 3 years and she is still eating the 11+ wet and dry but in a different brand and she is allot better more energy etc now she well be 15 in 3 days maybe you need to start to feed her 11+ wet and dry food for her if you are not already 

DO NOT BUY IAMS ,IAMS ABUSE ANIMALS

PLEASE, take your fluffy bubby to another vet! 

A second opinion is so worthwhile and often necessary if you love your bub.  I have had doctors like that before, too.

I find it strange that some vets (like people doctors) are wonderful, understanding and so helpful, whereas some tell you there is nothing wrong and to go home.  If you truly love your fluffy bub, if another vet - it certainly cannot hurt and may make all the difference.

Good Luck to both of you.  I hope you get the right answers.