Are my plants dying?

My plants are growing really well, growing lots of leaves, but on the sides of the leaves their turning yellowish brown, what can I do to stop this? I wasn't sure if it's because of those little bastard bugs living in my soil or what, the leaves are green except the outside, what can I do? Are they dying? I feel like something keeps going wrong with my plants, one day there leaning, one day one of them falls down, maybe it's something with my soil, but my plants don't seem to be getting stronger, and their growing extremely slow? Just a worried plant mama, someone please help this mama out

Much appreciated

If you posted up some pictures it would be much easier to help you. Based off of what you listed you could have anything from a simple PH lockout, to overfert, to bug damage.

^^^What he said. over fert, under fert. etc. etc.....

Old leaf fading? Probably under fertilized
New leaf fading? Probably over fertilized...
Generally