Stop loss/profit take issues

So the last few weeks I've been trying to get my head around trading, I've been investing for a good while now but want to try some short term stuff too on the side.

After much research I'm finding good entry points and good margins, but I'm stumbling at setting my stop loss/profit take. My problem is this..

So I find an entry point and buy in, I set a stop loss order to sell everything had the price drop out, no problem. But when I try and set a limit sell order I've got insufficient fund left to complete it, as it's all been deducted when I set the stop loss. Surely as the stop loss order is provisional I should still have funds to set another "provisional" order to sell the same said funds had they go higher also?

It's frustrating as I'm now in the position of either buying in and limiting my loss, but having to set alerts for a price rise and manually sell, or the reverse and risk missing a downtrend and having to hold assets until the market picks up.

I've searched and searched but all I find is issues with the orders executing etc. And nothing relevant to this issue, does any of the knowledgeable folk on here have any ideas? I'm sure I'm probably missing something obvious but it's very frustrating nonetheless!

Thanks in advance :)