Good typography is critical and weak type will always put you on the ‘NO’ pile, I’m afraid. You absolutely need to get that right. It is good that you understand that you are weak in this area. Half of any solution is knowing there is a problem in the first place.
There are thousands of books and links out there and a little bit of work on your part will easily find the information you need. A quick search around these forums will give you that information – the question has come up a good few times before. Here’s an extract I put in a post by someone asking a similar question, of some of the books from my own shelves:
You have the entire internet in front of you.
For what it is worth, at uni, type was not my strongest suit. It was a few years later that it ‘clicked’ for me, but all the groundwork we had to put in – history, hand-rendering, lettering – paid dividends. The hand rendering was one of the most useful things they had us do. Hated it at the time, but later realised how invaluable it was. Pages and pages of 10/12 Bembo, then on 14, then on 16. Hand drawing display type, etc. It all gives you an appreciation and understanding of how type works, the beauty of individual glyphs, how crucial negative space is, how the glyphs work together to form the whole. etc. Hard slog, but worth it.
These days, it is far easier than it ever was to find the information you need. Of course reading voraciously and learning as much as you can from the very best of the best is crucial, but a formal education also gives you invaluable staff and peer critiques. Without this, it is very difficult to get the kind of feedback you need. Places like this exist and you will always get good, honest critiques (even if you don’t like what you hear), but it is no substitute.
Naturally, I have absolutely no idea about your personal circumstances, but if you don’t get a formal education, unless you are one of those rare geniuses and naturally talented, then you are always going to be coming up against people who have found a way to get themselves educated. The best piece of advice I can ever give you is to get an education. However you manage it. Work you way through it, if needs be.
When I was interviewing, I’d say 99% of people who got through to interview had a degree. I can only think of one who didn’t and they had a real standout portfolio.
The advantage you have, of course, is that you have worked in a fast-paced environment (even if quality wasn’t always paramount), so you will have an understanding of production and print that many people going for the jobs you are going for may not. This goes a long way, but you need to ‘get’ type and there are no quick routes.
Good luck.