You don't have to buy a whole new laptop just because it 'crashed' - the operating system could be re-installed or the hard drive replaced by someone who knows what they are doing, saving you money and avoiding throwing away a perfectly good computer.
Did you have a backup of the data on your old laptop, including the iTunes Library you sync your devices with? If so, you'll need to restore this backup to your new laptop to continue syncing.
Without a backup your task to re-create your iTunes Library on your new laptop is going to be considerably harder and more time consuming.
See this post for some links to software that will help you transfer data from your devices back into iTunes on your new computer:
I'd suggest you buy yourself an external USB hard drive and some good backup software and start making regular backups of all the important data on your new laptop, to protect you against such issues in the future.