Answer: Hang in there! It could well be that your soil has a pH or nutrient problem, and usually these kinds of things take a bit of time to correct. I recommend that you contact your county extension office (ph# 223-8627) for a soil test kit so you can get the ball rolling soon.
The links below are to articles containing information and directions for fertilizing your plants though their leaves. Foliar feeding can't take the place of the nutrients that roots extract from the soil, but it may enable you to salvage some of your crops.
Seaweed For Plants
Fertilize with Epsom Salts
This link will take you to a page that helps you identify weeds in your garden. It's a good start, but you can also learn a lot from your neighboring gardeners. The extension office may also recommend a bulletin or book for weeds common in your region that aren't included at this website: http://www.rce.rutgers.edu/weeds/index-thumbnail.html
Best of luck to you!
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