The blowby out of my oil fill is massive

[SotoLogisticsLLC]

Hi guys, I was checking things on my truck because my oil pressure has started dropping lately. After an oil change, my oil pressure is fine, but the more miles I put on it, the oil pressure slowly drops. I do a pm every 12k to 15k miles. After about 7k miles, the oil pressure has dropped about 5psi. Not sure if it's related, but I started my truck today and opened my oil fill cap. I was surprised to see so much fumes coming out. My truck runs very well and is still very good at fuel economy. I read somewhere that I may just need to flush my oil. Any suggestions??