Hollow Knight: Silksong feels pretty difficult at the start, but as you progress and upgrade your equipment, the game starts feeling a lot easier. One way you can make the game easier is by collecting an item called Silk Heart.
Silk Hearts passively regenerate your Silk, which is the item you need to heal fast in Hollow Knight: Silksong, and use your skills. When you collect Silk Hearts, you gain one Silk for every Heart you collect. This makes it easy to fill up your Silk gauge, which makes it a lot easier to play the game when you face difficult enemies and bosses.
How Can I Get All Silk Hearts In Hollow Knight: Silksong

Silk Hearts can be found while exploring Pharloom in Hollow Knight: Silksong. There are a total of three Silk Hearts you can collect in the game, and they are pretty widely placed throughout Pharloom. This means the first Silk Heart can be obtained very early, the second one in the midgame, and the final one in the endgame. The location of the Silk Hearts has been listed in the following sections.
Location 1: Silk Heart Location In Mosshome

The first Silkheart is located in Mosshome. You’ll have to defeat the boss called Bell Beast, which can be found in Mosshome itself at the very top of The Marrow region. To get there, you’ll want to go right from the town of Bone Bottom, and from there, just head up until you hit a crossroads.
You’ll need an item called Silkspear to unlock the boss, because the path to the Bell Beast is covered in thick silk strands, and that skill is the only way to get rid of them. Once defeated, you’ll unlock fast travel and also get access to your first Silk Heart.
Location 2: Silk Heart Location In Whiteward

Whiteward is a location you reach much later in the game. It is connected to Coral Chambers and Underworks. Once in Whiteward, you’ll have to look for the Surgeon’s Key. You can find it towards the east of Whiteward. Use that Surgeon’s Key and you’ll unlock the Unravelled Boss. Defeating this boss will grant you the second Silk Heart.
Location 3: Silk Heart Location In CogworkCore

Cogwork Core is one of the final areas of the game, and you’ll get to fight Lace here for the second time. This fight is much more difficult than the one at Deep Docks. Defeating Lace will grant you the third and final Silk Heart.
How To Use Silk Hearts In Hollow Knight: Silksong

You don’t need to do anything special to use Silk Hearts. This is because, once you defeat the bosses as mentioned in the previous section, and acquire them, they get integrated into Hornet automatically. You will immediately notice the Silk regenerating passively and the effects in motion the moment you acquire it in Hollow Knight: Silksong.