Anxiety over leaving kids

Me & my husband desperately need just a date night to ourselves. Our youngest is 2 in a half and we’ve never been away from him all night but there’s a concert next month we would both would love to attend but I just cant bring myself to leaving our youngest. Ugh. How do I move past this anxiety. I feel like if we cannot start having “us” time it’s gonna end up destroying our marriage. I know this stage of our kids being young is only a short time but I also I know parents need time as a couple too. Any advice?