Ger,
I would think it sounds like a few things maybe.
You say you get a ringing sound. This might be nutt fault, ( the part where the strings are guided from the tuning keys to the fret board)
Also if you can only barr when a capo is on then I would think your action is too high. When you put a capo on it reduces the action of the strings so it would make it easier to barr.
I would suggest you get yerslef down to a music shop with no intention of buying a guitar. Ask to have a shot of some really good guitars and see how you get on with them.
This is not to say yours is not a good guitar. It might just need a little help from an experienced person.
If you find you can play other guitar ok and you do not want to change your guitar you can ask in a shop for advice. They would probably ask you to bring it in so they can have a look and let you know if it is worth doing anything or/and how much it would cost.
Ken
ye get some that are cut out for the job and others just get by from pretending