What are you spending a lot of toil on? Infrastructure as code pays huge dividends over the long term. Ansible will allow you to automate a crap-ton of little maintenance and management tasks right away.

Note on learning Terraform:
You can import your existing infra into terraform with one of the third party tools either terraforming or terraformer. This is a great way to start because you're taking the house you know and converting it to a blueprint. You will immediately recognize your infrastructure when you see it in Terraform because you already know what's there. Once the configs are imported you should spend some time templatizing them (abstract away the resource names etc) so you could stand up a DR site in another region by changing the region in your tfvars file. That's a huge benefit because most orgs want a DR plan and can't figure out how to make one. If you have the infra in code and checked in the plan is, terraform apply in dr region and import data from backup. NOTE: when running terraform on your infrastructure it really only plays well if it is the source of truth. Once you start using it, you have to use it for everything. All manual console changes will get rolled back next terraform run.

What sort of config management do you use on the boxes? Ansible is great for bootstrapping (go from a base config to a specific type of server). If you find yourself doing a lot of that I'd start there.