I can't figure out why my bill is expected to increase by 58% this month

If that's not possible, what do you do with the information "you will pay 58% more this month"?

It's a forecast, not a bill. In my experience it's quite a crude estimate, that looks at how much you've spent so far this month, and works out that, if you keep running the services at the same level for the rest of the month, here's what it will end up costing.

It's also worth mentioning that I believe these figures are before any Free Tier benefits are applied (not 100% certain as it's been years since my account was in-scope of Free Tier). For instance, your other screengrab shows 707 hours of predicted t2.micro EC2 usage. Depending on the region, that could be up to $10 on your bill. But once Free Tier is applied to your final invoice, all that will be wiped out, as you'll be under the 750 hours cap.

There are other things that you'll still be billed for even after Free Tier allowances are applied, because you'll be over the limit for e.g. Load Balancing.

In Cost Explorer you can get a projection of your monthly costs, though not split by service (you need to clear the Dimension section for this to run).

You can get a breakdown by service by setting the dates to be the start of this month through to yesterday, and this will show you the general trend of how much you're using each service per day.