My dog has severe separation anxiety and stays at someones house during the day, can I train her to stay home?

I adopted my dog Oreo from a rescue about a year and a half ago, and she is my absolute everything. 99% of the time she is perfect, well behaved, loving, and so smart! However she has a few anxiety issues. She has issues with several things, most are easily managable like thunder, loud beeps, and swinging objects (we joke my poor sweet girl is afraid of everything). But she also has pretty severe separation anxiety. She has gone as far as to scratch or even chew her way through first plastic and later plywood, and then jump from a second story window, on several occasions! (without any major injury fortunately) For a while she was on anxiety medication given to us by our vet, and that did help and we were able to wein her off of it. things were ok for a while until one day there was a big storm. This I supposed compounded her anxiety and she once again escaped from my bedroom window, and was missing for a heartwrenching 3 days. I was in peices, taking off work, searching for her day and night, and I am so so so lucky that we got her home safe again. After that I didnt want to risk leave her alone, so I started taking her to my parents house when I wasnt home. There arent any grandkids in the picture so my mom was happy to have her around, and they have several pets to help keep her occupied.Its been this way for about a year now, and all seems to be fine. Oreo hasnt had any issues with anxiety aside from the occaisional storm or other unavoidable thing, and she does not get upset when I leave her at my parents at all. But I want to train her to be able to stay at home, my parents will not be able to dog sit indefinately.Ive read a good amount but have encountered issues while trying to train her. She is accustomed to going with me everytime I leave, so once I try to slip out she is trying to squirm her way between my legs and doing anything she can to come too. She is about 65 lbs., and im about 110 lbs. and shes gor more muscle than me so leaving for even a few minutes is difficult. She ignores her toys and even food and treats so I cant distract her.I do have hopes of eventually getting a second dog, and have heard this may help. However I think I should have this under control first. How can I train her to be alright with me leaving without her? should I put her back on her anxiety medication? any suggestions?

First of all. I FEEL your pain. I have a dog who has done almost everything you described in your question!! She has broken out of a window on to my room, tried chewing her way through a steel kennel and breaking 6 teeth in the process, destroying my walls and doors, etc...I am veterinary technician and had access to all resources and it wasn't up until this last outbreak of anxious behavior that the veterinarian I work for suggested seizure medication. He explained to me that the brain does something very similar to that of a seizure when a dog acts out from anxiety. So we started with a low does of Phenobarbital (16mg) twice daily (once in the morning and once in the evening) and she has been doing ok thus far. Long term use of this medication can cause issues in the liver, so doing bloodwork on your dog regularly would be suggested. The only other suggestion I have for you is actually trying to kennel your dog. Granted, it didn't work for my dog, it may for yours. Some dogs find safety and solace in comfortable confinement and with your dog, you'd be luck if that were the case!! I would suggest starting slowly though. Bring the kennel to your parents house with the dog, have them kennel her periodically throughout the day while they are home and moving around the house, then try leaving the house for 5/10 minutes at a time, see how she handles it. Then just slowly increase the time she is left alone in the kennel. Do some research on kenneling and you'll find the same suggestions and maybe more! Good luck to you and Oreo! I know how rough it can be.