£2100 and no job isn't going to get you very far - I know that's not what you want to hear but if you want honesty, there it is.
First, you need a job, not only will it help you to support yourself and pay your own rent and bills, it will give you a better chance of securing a place to live - a lot of private landlords don't like DSS.
Secondly, if you're looking at the lowest rent possible you're better sharing a house in a good/safe area than renting a cheap flat of your own in a crime ridden area. There's a site called 'myspareroom' which might be useful - there's loads of similar sites if you Google.
If you really don't want a house share and you want your own place, then my advice is not to look at big major cities because with your budget you will end up in a bad area. It would be better with a small budget to look at smaller towns and even villages where you can rent for £300-400p/m in a nice area. The problem with that is - there is less work in less populate areas so if you do this you will need to do your best to get work there OR makes sure there are good transport links to nearby towns/cities that you could commute to for work.
Finally - you need to factor in your deposit and up front rent. Most landlords ask for at least one months rent up front, but where I live it's 3 months and a typical deposit where I live is £800. So before you've even moved in you could be paying £2300 UPFRONT. Then you need to consider furnishing because most private rents are unfurnished. You'll need a bed/sofa/storage units and in many cases a fridge freezer and washing machine (+delivery charges) plus everyday items such as cutlery, plates, kettle, - that is easily going cost £300+ and you're going to need to transport your current belongings to your new address.
Since you're a single young person under 35, you are not going to get much assistance in terms of benefits (take a look here:
http://www.nihe.gov.uk/single_under_35), so I cannot stress enough how much you really need to secure a job that pays enough to cover your rent and bills. It will be struggle, but it is possible - you need at least £15K annually - it will not give you a comfortable life, it will be difficult financially BUT that will allow you to live independently. So look for 15KP/A jobs in or close to a place with low rents and in the meantime find a means of raising some more money (sell your stuff) because ideally, you're going to need at least 3K to move out.