You learn to endure. You learn its part of the process of having these wonderful little beings in your life. Some people cannot handle it after all, and we understand that. A rat's life is on average 2 years but as we all know not even that long is a guarantee.
You have to think this. Pain, sadness, worry and expense in your life with them sharing it, OR no pain/stress/worry/expense and never having them in your life again. You need to weigh what is best for you and them.