Since you've already completed a psych PGY-1, it's possible to start as a PGY-2. The question you should ask yourself is "are you ready to be a psych PGY-2"? Are you ready to start supervising PGY-1's? Almost certainly not. Hence, you're probably going to need a PGY-1 position.
However, psych PGY-1 positions usually contain some number of IM rotations -- often 4 months or something similar. You don't need to repeat those -- I doubt they are really helpful in the long run, and you've already done them so should have credit for them. Therefore, what you could try to find is an off cycle PGY-1 position. If there was a program out there that has an open position in Jan or Feb, then they could take you there, have you do 6 months of only psych PGY-1 rotations, and then by July you're likely ready for a PGY-2 spot. off cycle spots are not in the match, so you'd just have to hunt around for them by contacting programs.
Restarting as a PGY-1 is certainly an option.
The 5 year gap is definitely going to be a concern. That you're a USMD and were a good candidate to begin will work in your favor. You will need an LOR from your old program -- you should request that now, you'll need it for any pathway forward.
You might be able to apply for an Occ Med or Preventive Med residency. Both reqire a PGY-1 year, it's possible that your psych year will count. These sppots are in the match, you'd probably need to wait until next year although you could try for this year.
SOAP would be a reasonable option for this year. To apply in SOAP, you need to apply to at least one program in ERAS. It can be any program, in any field -- you'll pay the minimum fees. You'll want that PD LOR, and whatever LOR's you can get. Then, in SOAP, you can apply to 30 programs total. Any combination of fields, but 30 programs. Can't buy any more. No cost beyond your initial app fees. Hard to say how successful you'll be, but the cost is low.
I'm hoping you have taken USMLE S3. If not, you have more problems.
So:
1. You need an LOR from your prior program. You should also try to network as much with them as they are willing -- they may be able to help you find programs with off cycle spots. You should assume and be up front with them that you are not looking to match there. You can hope they will take you back, but you shouldn't count on it. You should tell them up front that you don't expect them to take you back -- else they will worry that's what you're trying to do.
2. Apply in ERAS. Consider PM/OM programs if that interests you. If so, rech out to them as your app is very late and explain your situation. Not sure if the psych year will count or not. You can apply to psych programs but most/all will be done looking at apps. if you have any connections, use them.
3. Prep for SOAP. Come up with a plan. You have plenty of time -- it's in March. You'll have 30 apps, use them wisely.
4. Get clinical experience. Hopefully you have taken S3. If so, you can get a medical license in many states (although your long gap now may limit your options -- some state boards won't license you with the gap). With a license, you may be able to get some clinical experience. Again, use any connections you have. Start this process now -- it's long and slow, and you'll want clinical experience before you're applying next year if possible. Choose the field you want - psych, PM, OM, IM, or something else. Pathology is also low competitive, and they may care less about your gap. But you'll need some experience -- which can be easier since much of path isn't directly patient facing.
Best of luck.