Strange my "data use" skyrocketed suddenly after the unlimited plans arrived.

I've been with AT&T at least 15 years. I've seen it all. Approx 3 years ago my husband (uninformed and clueless-always tried to keep him out of AT&T!) stumbled upon an incredible deal they have yet to beat. For $159 he got 30GB data for however many lines (we had 5 at the time) to share. Prior to this I think we had 20gb and the entire bill ran $400+ a month. (Our highest expense next to the house payment) After he lucked into this our monthly bill dropped approximately $120 and since we have had it we've never been able to use all 30GBs of data, (and we have a teen daughter!) then we started to get the roll over when that was offered. I received constantly in last 18 mos specials if we would switch to this or that but NOTHING gave us 30GB for $159. Or came close. Then a few months ago that stream saver thing came out and the "unlimited" data where they slow you at 22gb.. EXACTLY 4 bills ago, with no changes in how we used our phones EXCEPT my husband actually passed away 11 mos ago thus removing one line and the data it used otherwise no changes but suddenly the last 4 bills have ALL gone over and had to have data packs totaling $45+ added EA month. Making the "unlimited" look good in paper. There is NO way in my opinion that this is a fluke! Absolutely not possible. Anyone else experience anything similar?? It's actually mind blowing To look back over the years and see how the bills would change tho our usage wouldn't, during certain times, like this for example! Because it makes me want to switch! No overages!!? After four months of paying An extra $45, reading no overages sounds pretty good! But! THE CATCH! Is In slowed down at 22GB AND lose my national discount. So IS it really all that?? I'm not so sure this con is worth it.