Seeing black flashes

Okay the title sounds weird and I have some explaNing I need to do. Im 17 almost 18. I'm near sighted, allergic to pollen, hypersensitive, have pretty anxiety, and currently have numbness.

I'm taking zyrtec for my allergies and b12 vitamins because of my numbess as they think that it's because of my low b12.

I recently noticed that I've been noticing flashing lights in the sides of my vision as well as in front and sometimes I see black spots too, they sort just pop in and out like there's lights blinking above me. It tends to happen more when my allergies get worse. I don't know if it's related since I believe zyrtec makes me dizzy, tired, makss my mouth dry, and I think maybe makes my muscles sore too but I'm not sure.

I haven't been to an eye doctor in a while to test my eyes, and have been to the doctor on Jan. 16 for my numbeness, while at the time I wasn't experiencing these flashes, she didn't really see any problems with my eyes when she checked.

I just want some input and advice honestly. I know people are going to tell me to go to check my eyes, but I want some ideas.