Hello all, old user, new name. Unfortunately I had to make a new account

Im coming here in search of assistance, input, anything that is an idea will not get shot down.  
I have a 15yo OTTTB gelding that I got off the track as A 3 yo. Run barrels, rope steers, open horse show slow classes, etc etc.  he is broke broke.  
I also have a 12 yo paint gelding heel horse. Also a pretty handy little fella. 
so on with the issue. .....I also had a 16 yo OTTTB Mare that I lost last spring due to a broken hind leg in the pasture

I am having absolutely no luck separating these 2. To the point it is dangerous for both the horses and myself and others.  Im kicking around options in my brain as to what to do to be able to enter shows,races etc etc. and not have all the screaming, pawing and tearing up stuff. While the other partner is in the warmup pen, class, etc. 

cannot afford vet bills, torn up trailers, and at the very most any one getting hurt  any thoughts that might help out are greatly appreciated, and no I cannot afford to sell and replace  ??  Am very willing to go to calming supplements, as long as they don't totally break the bank  

Anything?? 

Can they be separated at home - as in not in the same field/pen?

You could take one for a short ride in the trailer without the other. Start with a short drive and extend the distance/time away. 

Don't get them both out for work and rides together.

Start small, increase the time apart as much as possible at home. Then go to a show with only one.

I have the loafing shed set up with portable panels, that I can put  one in. 
problem being is I'm afraid the one will hit the panels or get hurt.  
they are off the scales buddied up!

Hauling a third horse helps tremendously for me, since their is never one alone at the trailer. If that is not an option, 1/2cc of guanabenz about 2 hours out is a game changer. It has acclimated them to the point, after several uses, that they are more "manageable" at the trailer and taking one away. Talk to a vet, since you will need a presctiption anyway. CBD oils work fine for some but are not a quick "fix." I'm not a fan of having to give shots, especially at a race, but has helped and they are better to the point they don't need that now and all of us are safer afterwards. 

Is the guanabenz only vet available and only in injectable form?  

the Cbd oils do not last as long as needed.  We are at open shows got this deal, I have put on my hands so I'm touching him with it etc, but they are just not long lasting Enough, and these shows are 2 day deals, it seems to wear off faster each time I use them. Unfortunately 

Guanabenz is perscription only iv. Two Bulls makes a feed version that lasts for several hours that comes in a oral liquid or top dressing that is very effective also. It is not a sedative but keeps them from going 'over the top' and has been successful with horses, bucking bulls and show animals. It is called DeStress. Lasts for hours. Amino acid based. They aren't huge marketers, but have a very effective product. Twobulls.net. You can also talk to the owner, JIm McClain, about it if you call. He's extremely knowledgeable. I know Kylie Weast is having lots of success with it as well, specifically on ones that wash out at the stall at shows. My apologies for not mentioning this sooner. When you mix the blonde and gray, things get tough.....

Thank you Holly!! I will check it out.