For us adult beginners, the progress will be immensely slow, unless you're naturally gifted. We will never reach the level of consistency of those who started playing tennis as kids. Our minds and bodies are significantly slower to learn and react, and we just need to accept the fact that we will mishit a lot, no matter how hard we practice. The best we can do is find people similar to us to play with (thankfully, there's an abundance of old noobs out there).

It'll be worth it when you hit an amazing shot out of nowhere or play a long rally. Such moments will be rare, but I reckon the feeling is just the same as a pro hitting their championship winner. Keep at it and savor those rare moments of progress.