Help Needed For Snickers The Pug

Hi, my name is Rachael and my 11 year old Pug Snickers has been experiencing "seizure" episodes throughout the past week. The first time an episode happened, he was pooping outside and he fell backwards completely. He started to spasm and he cried out in pain-lasted about 20 seconds. I took him to the vet that day for a full check up and explained exactly what happened, the vet wasn't convinced he actually had a seizure but experienced vagal nerve stimulation which caused him to faint while pooping. Snickers was acting completely normal after the incident-eating, playing and walking with no issues. Unfortunately 2 days later it happened again but this time in the middle of the night when I was sleeping. His violent movements woke me and his cry of pain. Our vet suggested blood tests and x-rays next, but I haven't had the funds to take him to the vet again so soon. I've been doing everything I can to come up with enough and Snickers was acting normal for the entire week with no issues. Sadly, a half an hour ago I took Snickers out to do his business and he had a third episode. My heart is breaking and I'm so worried. I hate having to ask for help, but anything at all would be such a blessing. Our vet gave us a treatment plan which includes full blood work, x-rays, urinalysis, fecal screening, ECG etc. I will try to attach a photo to show exact estimates but it's around $650-$700. Thank you in advance from the bottom of my heart for any prayers and donations for my baby.....-Rachael