My dental issues

I have always had issues with bad teeth - many cavities, and well it sucks. Then when we were no longer military and joined L3, I wasn't great about getting into the dentist. I finally did, and holy crap I have a ton of work. I used all my dental last year on a root canal and 3 crowns I think. Now I have another root canal and 4 crowns. When I had the root canal done last week, he wasn't able to clean the roots completely. He said they were S shaped and connected. Kills me because they told me that if I still have pain then I may need to have the tooth extracted and have an implant. That blow. He also mentioned that the tooth beside it might need a root canal as well (when the dentist thought it only needed a crown). When he was checking my teeth that one responded worse than the one I was in to have the root canal on. This BLOWS. So I am at the inbetween time between the root canal and getting my permanent crowns put on so I have to chew on my left side where I need two other crowns. Never noticed that side hurting before, but now I am chewing there - yeah those hurt too. One is cracked and one is broke. This weekend I also had my crowns fall off, so I went in Monday to have them put on. They used extra strong cement to secure them and pushed back my appt for the permanents. Well they fell off again that night. What the crap? So I am going back today to have them put back on yet again. It doesn't hurt but now my gums are really swollen from when they put them back on. I have already come out of pocket SO much and know I will have to pay a ton more still. This blows, can I just have dentures?