Gained weight and now i cant run normal ?😩

So i had a kid 5 months ago.. im still carrying the weight im at 164 pounds, birth i was 170 so I barely lost anything..... i was occasionally working out before i got pregnant but stopped when i found out.... i ran today just to the kitchen and back and noticed how big i am and my legs were aches and they hurted only seconds when i ran... wtf ☹️☹️☹️☹️☹️feels like my legs and whole body are heavy that i cAnt even run anymorr