Some puppies develop separation anxiety and some don’t, it is not fully understood. Whatever the cause, it’s important to realize these behaviors are not malicious and that they are likely to panic or other coping behaviors. Adjusting your puppy to being alone is the best approach.

It’s good for your angel to be comfortable when home alone. You can help your puppy learn this by taking a little time and following these simple steps.

Please start as soon as possible:

-Develop a schedule for your puppy and make sure your family stick to it.  
-Always give your puppy an opportunity to go potty prior to crating her/him
-You need to crate train your furry baby and she/he  needs to feel confident and calm in the crate.
-Crate your angel for short periods while you are present. For example, when you are watching television, put your puppy in her/his crate and put the crate next to the sofa. Gradually increase the time your angel is crated. Reward quiet behavior with calm praise. Start leaving alone in the crate. Start with just a few minutes at a time. Gradually increase the time spent alone
-Limit the attention she/he  gets shortly before leaving or when arriving home.
-When you let your dog out of the crate, remain calm and keep the greetings to a minimum. You don’t want to make your puppy excited.Typically, puppies aren’t ready to be given unsupervised freedom in your home until they are approximately a year-and-a-half or older.
-Try to make sure someone in your family is home as much as possible. Consider hiring a puppy-walker or neighbor to give your puppy a midday break while everyone is in work or school. 

Please do not give up on your puppy and please read all the comments and posts related to separation anxiety in our Facebook group. They will be super helpful and you will realize it will get better very very soon 

And here you can see Q and A-s about the topic in the Tomkings Frenchie Family Facebook group 
(if you are not member yet then you need to join first to see them)