Looking for advice on these last weeks with my first plant!

Hello,
This is my first grow and I was looking for people to give me advice on making my plant get back to full health. She's flowering and buds are clearly showing, I believe she's about two weeks in. I think she has nitrogen toxicity and i've tried to help that by flushing it out with about 8-9 gallons of neutral ph'd water. Some new growth is beginning to show signs of fatigue because they are turning yellow and the leaf tips are curling inward. Some major fan leaves have already died and I cut them off. The tips of the hairs on top of the exposed buds are beginning to turn a darker color but id say about only 5 to 10% of all the hairs are dark. Any tips or advice would be greatly appreciated to help me pull through these last 4 weeks or so.

New growth does not look to bad,let it dry.Needs to recover from the flood.
It does look to have a N , toxicity.Need to let it dry out really before I can tell anything.

I used Miracle Gro soil which I found out is a major mistake. I was watering it every day then cut it down to once every week and a half. I have never added nutes to it at all throughout the plant's entire life. Do you think I should give it nutes or just let it run its course? Any other pointers or rules of thumb about the flowering stage in general?