Weightloss plateau

I’m a 19 yr old female and it’s been a month since I started losing weight, I exercise 5 times a week and I sort of keep a “healthy”consistent diet. It was going well and I was seeing results until the last 2 weeks, my weight has stayed the same even tho I’ve been doing the same thing since I’ve started. I also work retail so I’m basically on my feet on most days. A few theories I’ve come up with is: I go to sleep at around 2 and get less than 7hrs of sleep. I forget to drink water during the week because of work. On top of working nearly all day I also exercise so I might be over exerting my body. What is your opinion and how can I fix it?