New to linagliptin...

Hello everyone, I was doing well but had horrible reactions to metformin... very loose bowels... changed to SR Metformin thought I was ok then sudden unpredictable bouts of it again. Very upsetting so contacted gp now on linagliptin...
Was checking on my bloods they were mostly OK but then at work was on my feet a lot Tuesday & by time I got home...could hardly get upstairs to my flat.!
All down one leg at the back was feeling tight... pulling & knee swollen, my toe felt numb too.... one next to big one ! I do have arthritis but pain was so bad I couldn't sleep.
Now my bloods are 10 in the morning... is this due to body fighting pain ?
Bloods before were about 7 in mornings...
Am taking codine & paracetamol for the pain & gp said I need bloods doing & xray too.

After xray & bloods found I have osteoarthritis in the knee & wear & tear in hip as well.
On codine 30mg but only taking it when I need to of a night time.
My bloods seem to have calmed down with readings below 7 in mornings.