I don't think you shot yourself in the foot necessarily. You have to be honest and assess your work against that of the more expensive pros who all have to make a living from it remember, and most at least will be seasoned pros producing good work. They'll also be having regular dialogue with the taxman - which you may not.
And what are your actual overheads? If you're using digital, you don't even have to buy film, so apart from petrol and processing costs, it's clear profit, so offset that against the actual time this is going to take you on a Saturday morning and it doesn't usually come out as a bad hourly rate. Having said that, you're charging my sort of bottom end price for nipping around the regiustry office and taking a few shots of the very small ten minute wedding at short notice.
Whilst I pitched my prices for larger church weddings well under the price of local pros, a Saturday morning would net me more income than a weeks pay in my regular job, but that was a situation I gradually worked up to. Comparing your prices with those of the pros is pointless, they have overheads you don't, and you're not making your whole living at it.
Start off modestly, get yourself a good name for the work you do, and you'll have no shortage of work rolling in. Gradually increase your prices as you feel your work honestly merits it, but bear in mind that there's a point where you stand to lose the job or they think they may as well pay that sort of money to a 'proper' pro.
