Permanent and Total

Good afternoon, I was wondering if there was veterans life insurance for a large sum amount to leave for three children that’s around $500,000 benefit. I am permanent and totaled and I’m not eligible for any time puff retirement VA insurance. I only served four years so I’m trying to get an insurance plan for that amount with chronic health conditions. I am over 50. If there’s any suggestions for me so that I don’t have to pay over $400 a month for VA life insurance please let me know.