Should I give up on these plants

[geeme]

Don't worry about the soil and you don't even need to fertilize yet - it looks like some/most still have their cotyledons and feeding the developing plant is the purpose of the cotyledons. Yes, temps will make a difference - they can tolerate down into the 50's, but they slow their growth when that occurs. At least, they slow their upper growth. Almost all plants go through what seems like a stall-out period, but what's really happening is they are working on developing their root system. Just be patient and try not to overthink things.

 

[Mallory]

In a mix of compost, vermiculite, fish fertilizer, blood meal, bone meal, perlite, garden soil
Water occasionally with diluted tomato fertilizer 6-4-6

 
That is a lot of fertilizer going on, and too much fertilizer can stunt plants. They will probably catch up once they are in a different soil.