I don’t really watch animes with lots of death but if you want something that will make you cry:

https://myanimelist.net/anime/33352/Violet_Evergarden

https://myanimelist.net/anime/35851/Sayonara_no_Asa_ni_Yakusoku_no_Hana_wo_Kazarou

https://myanimelist.net/anime/27775/Plastic_Memories

https://myanimelist.net/anime/36098/Kimi_no_Suizou_wo_Tabetai

https://myanimelist.net/anime/38000/Kimetsu_no_Yaiba

https://myanimelist.net/anime/9989/Ano_Hi_Mita_Hana_no_Namae_wo_Bokutachi_wa_Mada_Shiranai

https://myanimelist.net/anime/6547/Angel_Beats

Edit: Violet Evergarden is my top 1 favourite anime, I cried half of the time while watching it.

Grave of the Fireflies

Texhnolyze, incredibly bleak but probably my favorite series.

• shin sekai yori
• made in abyss

https://myanimelist.net/anime/44203/Seirei_Gensouki