One thing you can do to help yourself now is switch to paying for your shipping costs out of your pending funds. It won't help with packaging, but the shipping label is usually the most expensive part of those two so it makes a difference. The option is at the bottom of the page when you're printing a label on eBay, and it's "sticky", so it remembers your last choice.
As far as when they'll stop holding payments, just be patient. I believe it's 60 or 90 days they usually hold your funds (as in, that many days of selling), but they're not as consistent as many of us would like, so it could be sooner that they stop, or longer, depending on their view of your selling history.
Do you have any late shipments? Any cancellations? Any unresolved cases where eBay had to step in? Any of those could affect it, potentially.
