Cat is acting very strange

My cat named Whiskas is 14 yr old cat. He's been acting strange for about 2 hours, he can't get settled, he sits down for 5 minutes or less than meows at me and goes to a new spot and repeats, when he does sit down he is positioned very strangly. And sometimes if he's in another room he is meow crying. I think he may be in pain in his back legs becuase he sometimes limps and I touched his left leg and he got up from sitting down.

Take him to a vet ASAP.

Agreed!  - get him the the vet asap!  Definitely sounds like he's in pain.  Keep us updated as to how he is doing - let us know what happened!

Weird thing is he's now settled on my chair and hasn't moved for like 1h, if he continues to act strange I will take him to a vets, can't atm due to them being closed.

Please don't wait. Make an appointment for tomorrow am.

Absolutely, take him in as soon as you can tomorrow morning.