You need to get to a guitar shop and try out several guitars. They will (hopefully!) have been set up quite well. With a reasonable action and maybe not-too-heavy strings.
If you find they're better to play than your own guitars, then the problem probably lies with the latter. At that point, you need to either get them set up to be more playable, or take the plunge and purchase one of the guitars you tried out that felt and sounded good.
If those in the shop sound like yours, then the problem lies with you. Going to a teacher is an obvious first stage, if only for a couple of lessons. They will see almost immediately where the problems lie.
As far as the problem itself is concerned, there are several factors. But without seeing the guitars and you playing them, there are too many diverse reasons to offer remedies here.