I've been having aching feeling on both my hands under the thumb on the palm side feels like a cramp, it hurts to hold anything what should i do?

Tenosynovitis: Sounds like an acute inflammatory process involving the flexing tendon of your thumb. Range of motion exercises, antiinflammatories will help. An injection may be necessary.

Possible arthritis: Agree with dr. Villaplana in that it may be a tendonitis. If it is not improving, i would also consider possible arthritis. This can be diagnosed with an x-ray by your hand surgeon.

Get an X-ray: This could be a problem with your scaphoid. If your scaphoid is ok, then it may simply be common arthritis near the base of your thumb.