The short answer is you die in a suburb.

Think about this logically.

Carrying capacity is:
The number of people, other living organisms, or crops that a region can support without environmental degradation.

A long time ago, with low population density and but with lots of active hunting, they noticed that they had to carefully managed how often the hunted, what they hunted, and what age they took. This goes for flora (plants) as well as fauna(animals).

If they didn't manage this, it would kill off too many and the species declined. That meant that the camp would have to be struck, and the population moved to another location for those plants, animals, and firewood. Then they allowed time for that place to recover.

With the concentration of people in even the small cities, if suddenly people started gathering simply firewood for fuel, then allowing it to season (dry), then in a very short time it would be gone.

Two very useful plants are white and red clover. If the flowers are dried, a useful flour can be made from them, and this was used by the Scots to make bannock bread. They didn't use all clover flour, but they did use it to extend their regular flour. It everyone used that method, then there wouldn't be enough to harvest very long despite the fact that it regrows almost everywhere.

Cattail offer pollen that works the same way, but most people don't harvest it correctly by taking the seed head ealier as a whole section. You can also eat the shoots, and you eat the tubers for a lot of calories.

Same with squirrels. One could trap them, but then of course many younger ones would be caught, and they have peak periods when more are around. If people harvested acorns, blanched the tannic acid from them, and eat them in large numbers, then the squirrels would not have their food source.

There is not enough wild edibles to sustain a large population, plus lots of people tramping around will remove species quickly, damage the niche in which they grow, reduce animal runs by lots of human movement, etc.

Much of the problem is harvest time for that edible species and calories. Even if you had an abundance of game, much of it is low fat. You can in colder weather use up more calories hunting than you can consume and slowly starved to death.

Even if you put in a garden, unless it is carefully managed to maximize calories, and you preserved it by canning, then chances are it wouldn't be enough without livestock. Vegetables, leafy herbs, fruits and nuts are great, but not enough calories when working hard every day. Think a minimum of 3500 calories a day under stress. That's a typical MRE load for one day.

Don't take my word for this, but sit down and think what species are in your area, how many calories and nutrients they provide, vitamins and minerals, and then compare that to a workload under stress from lots of labor in gathering them.

This is why agriculture and animal husbandry lead to larger tribes than 500 members.

There are many herbs and animals you could initially harvest if you knew about them, and most likely for a very brief time. However, since we're in a drought, I highly expect that to NOT be the case since many will die. Much of the leafy herbs will die due to very short root systems. Some are perennial and they can hold out longer.

Tree crops will be vital, and there are books that are freely available which discuss them. Realize too that all the other species such as birds will be trying to harvest them as alternative food sources if their normal food source is absent. You'll be competing to collect things that are high up and not easily seen.

A drought coupled with a SHTF scenario is very bad. It means that any fishing will decline from people gathering from water sources, a lack of rainwater catchment, higher algae counts from concentration of what water there is, etc.