[help me please]

My BMW X5 model keeps dying on me so I just tried to drive my car and when I did my entire system started losing it and telling me I didn’t have a seatbelt on or that I was low on gas when both of those things weren’t true idk what I could possibly do because I have never seen this before and idk if it’s a battery issue or if it’s a computer system problem or what and another thing this just recently started when it got cold so I don’t know if that’s an issue too