Hi everyone!

I'm an ultra beginner to gardening (and by ultra beginner I mean never grown anything in my life) and earlier this year decided on a whim to try growing tomatoes from seed. I planted my seeds at the end of April, and my plants are now flowering and fruiting. The problem is that my leaves are in bad shape and I'm afraid they're just going to keep getting worse and I'll lose my plants and my fruit, and 3+ months of hard work will go down the drain.

Here's a link to some photos, so you can see the various symptoms I'm noticing. https://goo.gl/photos/qx5xubUTs57qRss49

I've browsed through tons of articles and guides for identifying tomato disease both in this forum and on the web, and I'm still stumped. In the pics you'll see some of these symptoms: leaves turning yellow, leaves turning brown and crispy on the edges and gradually spreading inwards (this is affecting my tiny tims, which are basically dying), new leaves that grow in super tiny (are these stunted?), warped leaves that don't lay flat, leaves that curl down and feel hard/fragile, darkening/discolored leaves, the list goes on... I can't count the number of times I've come across information on specific tomato diseases stating the cause could be either overwatering or underwatering... overfertilizing or underfertilizing... too much sun or too litle sun... I mean, how am I ever supposed to diagnose when it's always either/or? heeeeeelp! :?

To give some context on my urban garden:
- I have 16 determinate plants of 6 varieties (manitoba, rutgers, caribe, homestead, green striped zebra, and tiny tim)
- They currently live on the balcony of my small New York apartment (N/E facing), and get about 5-6 hours of sun in the mornings.
- I think I made the mistake of growing way too many tomatoes in one container (I have 2 or 3 in 5 gallon buckets), but this was ONLY after watching a youtube tutorial claiming that it could be done! Should I try and repot, or is it way too late??
- I water daily in the morning. I have no idea whether I'm giving too much or too little as I don't know how to quantify "1-2 inches of water per week" (suggested amount I've come across online)
- I fertilize once a week with tomato tone diluted according to the instructions on the bottle.
- I was out of town for one week at the end of July, and of course, that was the week we not only had a heat wave (90+ weather for 6 days straight with high humidity) but we had thunderstorm for several days.

I'm sure I've made a thousand beginner mistakes, despite trying to do research in advance, so please don't beat down my already wounded ego. Any other information I can provide? Would really appreciate any insights or helpful suggestions to improve my plants' health.

Thank you!!