Can I receive money after an accident even if I had preexisting health problems?

Yes. The fact you have a preexisting health condition will not stop you from making a claim and recovering for your injuries and losses. Whoever causes the accident takes you in the condition you're in at the time of the accident. If the accident makes your condition worse, then you can recover compensation for the worsening that happens. The fact that someone in better health would not have been hurt as badly as you were does not make any difference.