[jacquesm]

Well, you can continue but then you'll just crash harder. Talk with your co-founders (assuming you have any), explain the situation and tell them you really need time off. It's a very good test of how solid your co-founder relations are, if they understand and let you take a break your company will likely succeed because you are capable of dealing with crisis in a constructive way. If they force you to stay or if it results in a fight then most likely in the long run the company will not do well because it does not know how to deal with unforeseen events.

Whatever happens: you take that break. Otherwise the price only gets higher.

Companies can become millstones around your neck, if the company is now selling to a few thousand users and you are able to draw a small salary a break should be possible. After all, if something else that is serious (say a car accident) would happen to you then they would have to cope with that as well. This is fortunately something a lot more controllable than that.

FWIW any company with more than 3 people should be able to continue to function for at least a couple of months without major change if one of the principal players has to bow out. Life happens.

As for the recovery: try to do as little as possible, and if you do decide to do something make sure it is as physical as you can stand. That's the fastest way to recovery.

Best of luck to you.