insecure or hormones??

Why i feel so insecure everytime i see these girls on ig or fb working out or with a nice body i just wish to be like that. im thinking after i give birth to work out and stick to a diet, but lets be honest with a toddler, a new born, wife and work how can i do this, also i think of going to DR and have my body done. but theres fears in me. im not big at all if i have to lose weight i will say 20 pounds no more, but i feel like im still young im 30 and thia is when i want to look good