By pulling the 5* weapon, you reset your pity count to 0, meaning you have to pull 90 again for a guaranteed 5* - which can be another weapon again. If you want characters, go to the limited character banner. To answer your second question, you practically have same chance every pull for a 5*.

Do weapons count as pity Genshin?

Pity in Genshin Impact doesn't carry over between different types of banners. For example, the Weapon Event Wish and the Character Event Wish banners both have different pity counts, meaning you'll have to build pity on both banners if you want a guaranteed five-star character.

Do weapons reset pity Genshin?

At the 90th pull, you will receive a 5-star character no matter what. For the weapon banner, the same applies around the 65th and 80th roll, respectively. When a 5-star is obtained, the pity count resets to 0.