Plz help..........................… :)?

Well im 19 and I graduated,frm highschool almost 2 yrs ago. when I was in high school I was very social and always had something to talk abt,with my friends,i was always wearing the latest fashions and stuff . Im getting married soon and people havd told me that married people get fat and stop taking care of themselves I have noticed tht I dnt dress up or wear makeup alot when I go out and I have gained some weight nt alot but enough tht its noticeable im worried that once I get married ill get fat and all stuff how can I take care of myself so it wnt happen . Btw I work 5 days a week 9- 6 and I care for one chihuhua mix three bunnies and one cockatiel