Prim grass/flowers giving me very low FPS and lag

[Venus Petrov 333]

Indeed, those types of environments can cause you to experience lag.  I assume by reducing your performance, you have also reduced your draw distance (from the photo, I cannot tell).  Here are the minimum and recommended system requirements:

https://secondlife.com/my/support/system-requirements/

It looks like you might benefit from getting a better graphics card.

When you go into Edit  > Preferences > Graphics and click the Recommended settings, what do you see?  Moving it up from the recommended setting may cause some decrease in overall performance.

[Venus Petrov 333]

Indeed, those types of environments can cause you to experience lag.  I assume by reducing your performance, you have also reduced your draw distance (from the photo, I cannot tell).  Here are the minimum and recommended system requirements:

https://secondlife.com/my/support/system-requirements/

It looks like you might benefit from getting a better graphics card.

When you go into Edit  > Preferences > Graphics and click the Recommended settings, what do you see?  Moving it up from the recommended setting may cause some decrease in overall performance.