This seems like a pricing issue (for your firms non-existent profit)... But more on that in a bit.
I'd be curious to know your brand awareness and brand loyalty (which gives you your brand total you see there). To find that out, go in products, select the product you wanna see (so Cola, cigs or meat) and check whats your brand awareness. This is the rating affected by advertisement. I usually max advertisement for a product in the first month or 2 to get that rating to 80, just to maintain my brand awareness around 80 while my brand loyalty picks up. At that point, I keep advertising at 50-100k or so a month for a product, per media. When brand loyalty + brand awareness total gives me 100+ in brand, I can start dropping the advertisement to drop brand awareness while maintaining a 100 rating in brand, thanks to my brand loyalty raising all the time.
Please note that I advertise for a product in the 3 medias at once, per city, at all time. I use warehouses to do that (3 warehouses per city for advertisement, 1 media per warehouse, you can advertise 8 products at once using that system. Its simple and leaves my factories and retails stores slots open for more important things, like production and sales
I avoid letting a product overall getting too high as this means the price isnt high enough. You dont want, as its your case here, to have a city overall that high, as its a pain to get it down later on once you control the market (dropping price little by little to make your overall, and therefore the city's overall drop, then you drop the price some more, etc...). From 90 ish to 60 or so would make a while and alot of management, or you can just hike the price a big chunk at once and be done with it. In that case tho, you'd suffer a huge brand loyalty penalty (I'd avoid doing that).
I'm not exactly sure how low you can get your product's overall in general (while keeping it above the city's overall) without getting a penalty in brand loyalty. I'll be checking that in my current game. I know at 60, you wont have a problem at all (meaning brand loyalty wont begin to drop, from whatever number you previously had, as long as you keep your product's overall above the city's overall by 2-3 at least.
From that screenshoot, I can tell you dropped the prices early on to gain market shares and didnt rose the prices back up once you were controlling the market. You now end up with products netting a minimal profit margin. A better way to get a new market isnt to drop the prices (to avoid the issues you got right now later on) but to to an ads blitz, just to get your brand awareness to at least 80 in no time. This'll help your product's overall alot (always depends on the importance of brand % for a given product: for example, the brand % for cola is usually over 40%, up to 48% in some cities) This means you'll be able top raise the price alot as soon as your brand awareness gets near 80 or so. Just rise the price top get your product's overall down to 60 or so.
This of course always depends if you got competition for market shares in the city. Dont drop your product's overall below your competition product's overall
I normally net about 4-5m (profit) easily in a 4m city by the end of the first year or so with a convenience store selling Colas (3 purchases inputs, 5 sales and 1 ads unit, which becomes a 6th sales unit later on when I began using warehouses, when money allows). I also normally build 2 conv. stores in big city (4m) so thats 4m $ x2, so 8M profit at least per month in a big city.
Considering the bars you got there, its obvious you cant meet the demand on any of the products. Baring the fact its not a supply issue from your factories, I suggest raising the prices. Do that while checking your brand loyalty. You'll need to add retail stores also to keep up with the demand. However, fix your prices first. Useless to open other retail stores, this wont fix your profit issue. This is a pricing issue here.
