How can I improve my organization's newsletter?

Our organization started sending newsletters with constant contact to our connections in the past few months. We are really struggling with interactions, opens, and clicks. We believe our newsletter design looks good, but maybe it needs some adjusting, or different content? We would welcome any advice that you have to share. Please see the links to our latest email campaigns. 

Thanks! 

March - https://conta.cc/3Nwztax

April - https://conta.cc/3LHbDrh 

May - https://conta.cc/3zalhzb 

June - https://conta.cc/3uhE6NK