I feel your pain. I have a ton of scuba, freediving, spearing, offshore fishing, inshore fishing, fly fishing, hunting, archery, backpacking/hiking, snowboarding, boating, wakeboarding, RV, etc, etc, etc, gear. It's TOTAL insanity.
1: I also use bins and large duffle bags. Labeled. No other way around it. I store most of the bins in my garage in the off seasons, then as the new season/activity approaches, I rotate bins and move the items into a spare closet in my house. This closet has room for a very small shelf, also hangers, and a little overhead for larger items. This system works pretty well.
2: Sell/give/toss your unused crap! This is a hard one for me... but there's gear I have that I haven't touched 5 years... some even 7-10 years. Not good. Stuff like old/out of date reel, rods, scuba booties, gun slings, etc. Look through all of that crap and put it into a "for sale bin" (most likely multiple bins. My rule is if it's not going to bring me at least $10 (after shipping) and can't be easily put into a USPS Priority mail box/envelope, it's going in the trash. Or I happily give stuff away if I know someone could use it. If it's a commonly used item, I list it on ebay for .99 cents. It almost always sells for he right price. More valuable stuff I list appropriately of course. If your kids are old enough you can also give it to them to list and they can keep the cash.
3: Upgrading. When you upgrade, sell the original item. I am in the habit of keeping it as a backup, for my kids, for my wife, etc. None of that ever happens. Sell it... it's got the most value then.
The struggle is real brother! That's my 2 cents... hope it helps.
Edwin