Apologies you went to bed crying, ladysybil, but it is far from clear just what aspects are a priority.
I can see that if DS1 cannot be bothered / trusted with a mobile phone, manage to charge it, let alone look after it sufficient for it not to get lost, then a laptop is way down the list of things to consider, until proven able to keep a 10 quid mobile safe for 4+ months, charge it, and not just leave it in the safety of home so it cannot get lost.
I don't know whether you did buy an expensive laptop for yourself, or whether someone latched onto your post where you suggested a budget of 600+ (back in September), which I assume was for consideration as a purchase not for you but for DS1. However, if you had the cash then, did some of it get spent on presents for Eid ?
My main 'gripe' has been about having an iPhone on contract which is probably not an essential, and is costing how much per year ?
As you've indicated, finances are a whole different and lengthy subject, but rather than judge you a poor parent, maybe you can see from our side that we don't know how your DC feel about how Christmas could have been spent, what you did for Eid, whether you bought a laptop for yourself (or not) and so on.
Having an iPhone, posting about whether to get the iPhone 5 when available (which implies continuing with a contract, probably costing you 300 or more per year... and that could be on the low side) does seem a bit off.
You've been feeling guilty about not being organised enough to put some cash in an envelope, and having seen the amount some others have spent (whether it be 50 quid or 150 quid (*)), it is much more than you spent. Now that's perhaps understandable if Eid presents were significant, but not quite so understandable if food, clothes, and heating a large house are used as justification for limiting spending on gifts.
I have no wish to be mean or pick on you - I have questioned one or two aspects, such as spending on a mobile where the saving could easily be put towards other items, unless you fee your mobile needs to be an iPhone rather than a cheap PAYG where could top up with a fiver a month, or less frequently...
I seriously doubt anyone can justify needing an iPhone or Android, or one of the more costly Blackberry, unless such a device is paid for by an employer as they insist on it for compatibility with other employees and facilities expected to be used by staff.
(*) to be honest hearing of some spending several hundred pounds in total [whether for a partner or each child] does seem excessive to me. I have known some go to excess, such as a couple [distant relations] where they had 24 gifts each, one for each hour of Christmas Day, and not small cheap gifts either, I expect each item would have cost 50 pounds up ... and that was around 15 years ago.