after 8 years of being divorced - what do I do to
get it modified? I live in a different county than
the county that the divorce was finalized (same state).

>>>>>>>>>>> File for modification in the county that originally had jurisdiction , ask in the petition for a change in venue to where you live now , if needed .

Do I need to consult a lawyer or what???

>>>>>>>>>>> You could request assistance from CSE .

was based on 50/50 visitation and it is more like
75/25 (me being the 75 percent) and the ex does not
pay court ordered medical insuranace.

>>>>>>>> In some instances , when CS is calculated the actual amount of visitation utilized ( when not the same is the CO'd amount ) will be used to determine the presumptive amount . Were the costs of insurance premiums deducted from the ordered/agreed amount of CS ?

If, at any time while a child support order providing for an insurance adjustment is in effect, such insurance coverage is
allowed to lapse, is terminated, or otherwise no longer covers the children for whose benefit the order was issued, the
court:
a. may find the amount deducted from the obligor's child support obligation therefore to be an arrearage in the
obligor's total child support obligation;
b. may find the obligor liable for medical expenses that would otherwise have been covered under the insurance;
and/or
c. enter such other order as it shall deem appropriate.

Anything could happen .