The good thing is dogs only go into heat twice a year, instead of monthly like many other mammals. Or practically 24/7 like cats. :lol: So you just need to get through the next week or so if they'll be fixed in October. You can do it! :thumbsup
Sounds like Littermate Syndrome. There's a lot of articles online that you may find helpful. Tips and tricks to help them become more confident when separated.
For anxiety, I really like the product Rescue Remedy. It's a natural product and it has worked well for me each time I have used it on...