#tldr is above the readmore. below is more detail and his reasoning

[noamuth]

Bloodletting

As a part of his worship to Lolth, Dalamus practices minor bloodletting, a ritual sacrifice of his own blood, typically a few drops from his fingertips allowed to soak into a page in his journal.

In Menzoberranzan, Dalamus had a shrine in his home dedicated to Lolth which he offered prayers and thanks to. In times of stress, he might prick or cut a finger and offer a small amount of blood in the hopes it would change his luck. If his day or week improved, it was assumed to be because his blood had pleased Lolth. By contrast, if nothing improved, he took it to mean he had not offered enough.

Now on the surface, every day is fraught with stress, and this bloodletting is more frequent. After learning of his Matron's abandonment of him, he repented that day for his continuing to draw breath with the blood of his palm and multiple fingertips before returning to his typical "schedule". He believes if he can just continue to prove his loyalty and hold off Her ire until he defeats the Absolute, then perhaps all will be forgiven and he can return to Menzoberranzan. Perhaps not back to Nedvyllanna's side, but back to being a commoner.

He always does so in the privacy of his tent. In lieu of a shrine, he settles for drawing Lolth's symbol in his journal and letting the blood soak it. He keeps his blade clean, cleans his wounds, bandages his wounds afterward, and may take a small sip of a health potion to accelerate healing to prevent the necessity of multiple bandage changes.

Even with a healing potion's help, soreness may linger a bit longer than the wound itself, making stone polishing difficult or painful depending on which finger(s) he chose to use. This, he thinks, is just another way to show Lolth his loyalty--that he is willing to temporarily pause his gemcutting to assure Her that She comes before all else, even if being unable to work with his hands is legitimately upsetting to him. The upset is part of the point.

Despite its consequences, the bloodletting itself has become a strange soothing activity. There is a rush of relief at seeing the release of blood, a sense of accomplishment, of doing well for his Goddess. It is something within his control, and something which he believes pleases Lolth, or at the very least delays her ire for another day. He relies on it so much that missing more than a day without some kind of dedication to Lolth--be it his blood or someone else's--causes distress.

He worries that if he displeases Lolth, especially now knowing he was meant to die after his exile, She will somehow "catch up" to him and punish him. The reality is that Lolth likely does not care about him at all, if she even bothers to sense his existence anymore.

~

He does eventually break this habit with help and support and the promise that nothing bad will happen to him if he stops. It takes an intervention--confiscation of sharp objects from his tent, and a willingness to hang out with him when he becomes antsy--but it does happen.

The release from that fear, realizing that Lolth is not going to punish him for not bloodletting, is enough to move him to tears.

Even far into the future it remains a tempting fallback when incredibly stressed, but he gains healthier coping mechanisms to use instead, as well as having more people in his life he trusts to talk to.