Is this Hemokatín Bloodline (Human-Human or Human-Lesser Vampire) Subrace Balanced?

Parent Race: Hemokatín Vampire

I am going to use all of the traits as if I were following the traits for a Hemokatín of each of the 6 subraces. Please note that I will not be putting Age or Alignment traits here. All 6 subraces are Chaotic Good (Usually), and mature faster than humans and live to 750. This is all for D&D 5e.

The first subrace I’m focusing on, Bloodline, has the following traits:

Bloodline Hemokatin

Ability Score Increase. Your Charisma increases by 2, and one different ability of your choice increases by 1.

Size. Bloodlines are the exact same size as humans. Your size is Medium.

Speed. You have a base walking speed of 30 feet.

Bite. As an unarmed strike on your turn, you can bite one willing creature or a creature you are grappling. If you hit a creature other than an undead or construct, you deal 1 piercing damage and 1d8 necrotic damage, rather than the bludgeoning damage normal for an unarmed strike.

If you do not use this attack against a creature within 3 weeks, you go insane: You gain the poisoned condition, and you undergo the effect of the confusion spell when you take damage in combat.

Darkvision. Due to your relationship with vampires, you have superior vision in dim light and darkness. You can see in dim light within 120 feet of you as if it were bright light, and in darkness in the same radius as if it were dim light. You can’t discern color in darkness, only shade of gray.

Keen Senses. You are proficient with the Perception skill.

Advance Grappler. When you grapple a creature, you are considered proficient with the Athletics and Acrobatics skills and double your proficiency bonuses for those skills.

Light Sleeper. You only need to sleep for 4 hours out of a long rest. The other 4 hours must be spent performing light activity, as normal.

Undead Constitution. You have resistance to poison damage. You also have advantage on saving throws against poison, disease, and being put to sleep by magic.

Sunlight Sensitivity. You have disadvantage on Wisdom (Perception) checks and attack rolls that depend on sight when you, the target of your attack, or whatever you are trying to perceive is in direct sunlight.

Skills. You are proficient in an additional two skills of your choice.

Tool. You are proficient with on tool of your choice.

Minor Illusion. You know the minor illusion cantrip.

Languages. You can speak, read, and write Common, Hemokatín, and two other languages of your choice. Hemokatín is a secret language similar to theives’ cant.

Here are what I think is unbalanced:

Bite. Too much necrotic damage?

Skills. Three skills seems a lot, especially when you choose two.

Is this subrace balanced with the other D&D 5e races, especially those with subraces themselves?