Can a baby forget his mom? 😞

Panda
I'm a FTM.. My son is 4 months old. Earlier I started pumping milk for few reasons and now he's refusing to breastfeed. So we are exclusively pumping and bottle feeding. I'm with my mom for a short while, so she's also taking care of my son. I'll be going home after 3 more months. 
For now I feel that my son is more attached to my mom than me. I feel that he likes my mom more than me 😞 I feel so worried that will my son forget me? Will he long for my mom when we get back home? And some times I feel more possessive and start fighting with my mom 😞
Help me ladies !!