A consultant that is separate from your securities attorney can help you navigate this, but a competent securities attorney can help as well. 

Due to seller's financial needs however, a full cash-out offer was ultimately agreed upon, and a conventional commercial loan with a 10 year term amortized over 25 years with 27% down was secured.

But what am I supposed to do in this situation that I'm in where I feel like I have no security that he has my best interests at heart?

They secure the money they lend to you with the asset.

I secured the HELOC and have been actively hunting for our first deal (my dad and I).

Typically these type of dispensaries have heavy security and I am not aware of there being any issues regarding theft, etc in the several years Colorado has had MJ approved for recreational use.

Money isn't abundant and I'm no where near financially secure.

That is what i'm seeing now, are you familiar with having a seasoned investor with those requirements sign as a "Guarantor'' on the loan to get qualified and secure the funding as a newbie investor?

Think of all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.

Portfolio means that the lender will hold the loan on their books and it will not be sold off to the secondary market (Wall Street as MBS or Mortgage Backed Securities).