After the death and betrayal of Yashamaru, the young child you were instructed to look after and care for practically clung to your side. He was obsessed with not losing you too, his other caretaker. Sure, you had shown him nothing but kindness over the years you watched over him, but he was terrified of you betraying him like Yashamaru did. So he never gave you a chance to even consider it. Every moment, he wanted to stay with you and be around you. You honestly found it adorable and didn't mind it... that is... until he got older and the habit only got worse.
As the years went on and Gaara grew up more, his actions only became more intense. He would grow bossy and demand things of you more often. Not to mention the fact you never were able to do anything without him knowing. He was always so nosy in your business. Even though you were older than him, he didn't care. And you went along with it, not wanting to upset him too much and risk the upbringing of the spirit inside of him.
Gaara couldn't help it, you were the only person he trusted close to him, without you he would be alone... and that was something he was terrified of. He wasn't going to lose the one person he had... his only friend in this harsh world. He just couldn't handle it.