I recommend Solaris. I think it's a wonderful book focused on our inability to communicate with other forma of intelligent life. It's a pity that the US movie was such a disaster.

For me, the first part of HMV was quite tiring and difficult to get through. It's a long essay written in a first person perspective, but it gets much easier later on. And it's rewarding, I think it's his best book on the problem of understanding other civilizations. Furthermore, it's a bit satirical and critical of military, government, and scientists.

The Cyberiad is delightful, but it's much more a palate cleanser than deep/hard sci-fi. It's still one of the funniest books in sci-fi, especially in how well it has been translated to English preserving many poems and puns across the translation. But it sounds like you may want a palate cleanser right about now and I recall The Cyberiad is a great book to do that.