Of course you aren't too old for playing guitar. First of all, the F barre chord is something EVERYONE struggles with. It takes time to get your hand to get used to it, but also takes time to build up strength to actually play it well. Even I and most pro's mess up the F chord with not every string fully ringing out the way it should.

So again: THE F CHORD IS SOMETHING EVERYONE STRUGGLES WITH, PERIOD. That would be rather called a fact.

Secondly I think it is really useful to practice chord progressions and THINKING about your move. So how can I easily change my fingers to make up the next chord. This is something you should take time to practice. Look what the purpose of each finger is and the way it should be set up to form the next chord. Sometimes you can slide a bit or move fingers up and down. That should get you confident with every chord. Also I would recommend taking it slowly and perfectly and after that speeding it up. Doing something fast and wrong is a very bad habit. Your brain will somewhat re-do the proces, because unlearning something is harder then learning something new.

JJ