I have a Masters in ITIL, (that's MSc) plus the Managers Certificate.
It's a great way of learning the framework - but to back someone else - the application is the key thing. Honestly I don't use it daily - in fact not for years, but the principles are sound and ensure you look at the wider scope of things.
Secondly, I'd try to get someone else to pay for it. You have a lot on already - so I'd do the foundation certificate - and then look to a large employer to potentially take you through the Managers course.
Thirdly I'd recommend you consider professional memberships as well. With your existing skills try the BCS, for CITP. I wouldn't go for any other memberships beyond that. If you need a referral for CITP let me know and I'll be happy to give you one. The only reason I recommend BCS above the others, is because of the access you get to various networking events and so forth - which might help you going forward.
Best of luck.