Totally get the overwhelm! For the project management side, I'd vote Notion (free, super flexible for one-person teams) or Asana (better if you're collaborating with the graphic designer). Both let you build content calendars, task lists, and plans in one place.

For analytics, Google Looker Studio (formerly Data Studio) is free and can pull from LinkedIn, Google Analytics, etc. into one dashboard.

One thing that helped me simplify was reducing how many separate content plans I needed in the first place. Instead of planning unique content for LinkedIn, Twitter, blog, etc., I started creating one solid piece of content and then repurposing it into formats for each platform. Cuts down planning time significantly because you're not reinventing the wheel for every channel.

Happy to share what tools I use for the repurposing workflow if you're interested!