Very much agree with the second point. And not just how it relates to the actual project work, as a freelancer, you also need to be prepared to do a lot of things that aren't development. Tools and consultants are available to help, but invoicing, insurance (if applicable, depends on your client types), taxes, proposals, etc etc all have to be overseen by you if not actually done by you. Personally I have been fine with those tradeoffs, retaining a high degree of autonomy in exchange for some less than interesting tasks. But it's a tradeoff you have to be willing to make if freelancing is going to be the source of your livelihood.
Edit to add: especially if the target client js less than savvy, they're going to really appreciate working with a consultant who has the skillset the OP does. Frequently (and sometimes frustratingly) less savvy clients can take a very wide view of what a web consultant should be providing for them. Marketing as a product development and management guru can absolutely become a viable business as a freelancer. There are tons of other freelancers with other specialities whom you can sub to (if the budget and agreement allows) to fill out any gaps you may have in specific areas. Particularly things like design and UI that lend themselves to well-defined scopes and deliverables.
I was in a very similar situation about 6 months ago, but with even less of a runway (sidenote, lesson learned there). While taking a whole month as R&R time is not really adviseable (plus 12 new next big JS frameworks will come out in that time, right??), I will say that taking a week or even a few days as a brief pause is not a bad idea. I needed a few days to get my head on straight and to push through the less productive emotions that are inevitable in that situation. Though it sounds like the OP is already a lot less angry than I was.
Edit to add: especially if the target client js less than savvy, they're going to really appreciate working with a consultant who has the skillset the OP does. Frequently (and sometimes frustratingly) less savvy clients can take a very wide view of what a web consultant should be providing for them. Marketing as a product development and management guru can absolutely become a viable business as a freelancer. There are tons of other freelancers with other specialities whom you can sub to (if the budget and agreement allows) to fill out any gaps you may have in specific areas. Particularly things like design and UI that lend themselves to well-defined scopes and deliverables.