Hello @derekk,
thank you for joining! I am sorry to hear that you are experiencing issues with increasing your sales. It’s good that you already took the time to optimize your listings. Everything what you mentioned would be helpful, including A+ content and PPC. What is your business model?
If these are private label products, then social media activity should help - you need to work on building your brand’s presence. Also, I would highly recommend you to try Amazon Vine - this will bring you product reviews and extra sales.
I would suggest you to review the following threads regarding the matter, which may help:
I hope this helps. Please feel free to post here whenever you need help.