There is money missing from my checking account!!!?

A few months ago i inherited a decent amount of money, since that time I have pulled out a lot of it to buy things car, pay rent, tv, etc. Anyways, I basically cleared out the account leaving exactly $405 and I’m 100% sure of that. When I first was told about my account they told me if I dropped below $500 they would send me a check for the remainder of the money and close my account. So for quite a while I was expecting this check to come it didn’t so I called an automated system to check my balance it was 405.67 just like it previously was. A few more days later I got impatient and needed cash so I went to have someone cash a check for me(my bank is out of state and I don’t have any other bank so I have used close family to cash all of my checks) anyways i call to check my balance one last time and it says I have $00.00. So I’m like wtf is going on. So I wait about a week and call back because I still hadn’t received a check and it still says $00.00. So am I never going to see this money again? Also I tried looking for my bank statements online and couldn’t find them anywhere my bank is The Northern Trust Company from IL and it’s through Jackson National and I’ve tried both of the sites and cant find anything. If anyone has any advice please help me out here, or if anyone knows where I can check my statements or something please let me know. I desperately need the money, I’m supposed to start school/work rather soon and my car is been messing up a lot and I desperately need it. Thank you for your answers
no links to anything please