Bike Sizing

https://www.slowtwitch.com/Bike_Fit/index.html

I'd spend some time here ^^^^ before I invested in a tri bike.  You need to know at a minimum your stack and reach numbers to determine if a frame will work for you.  I'm 5'10 (fairly normal height male but with shorter legs).  My stack/reach numbers only fit some of the popular models ... for instance, I can't get a Cervelo to work for me. 

You can also do a LOT of tweaking if the bike is in the right size range, but it will be an added expense (pro fitting, new parts, etc).  So consider the trade offs.

My gut is that this bike is too big for you.  I personally think it's better to be on a slightly smaller bike - too big and it's really hard to make right.  I've had many a bike salesperson try to convince me of this, putting on different handlebars and stems, moving the seat, etc.  Just never seems to work.  Although this may be a small person's problem...   But if you look at what pro riders are on, they are always tiny.

No matter who, or what bike, I always recommend test riding a few bikes so you can see which brands you like.    I got into a new bike category this spring and the bike I thought was *perfect* for me based on specs felt awful.   I know you said you didn't have a lot of options, but spend a little time with what you have.  It's worth it.  Also, test the used bike as much as possible before buying it.  Go with your gut.

The thing about triathlon bike fitting...you don't know what you don't know.  Go to someone who can guide you.  Here's a list of fitters in Michigan...looks like a couple are in Ann Arbor which s/b fairly close to you. 

https://www.slowtwitch.com/fitters/statelist.php?state=michigan