I know it's not typical for investors to include debt service or mortgage payments in their NOI, but that's usually when running numbers for partners or banks so that they get an accurate view of the cap rate. The reality of it is, if you are planning on living at least in part, on the cash flow, you have to include it in some form- either in your rental budget or your personal budget. A quick estimate would put your principle and interest payment around $1250 per month. Typically with a down payment that low, you would have to carry mortgage insurance, unless your appraisal comes back at 20% higher than what you are paying. I am not sure if that is waived with an FHA loan, someone else on here can certainly speak to that.
In any occasion, if you can house hack and get tenants to pay all or most of your mortgage and you are confident you are getting a good deal, then there's a good chance it will pay off in spades. I wish I would have started that way.