What you're looking for doesn't exist.
IF you were in perfect health, with no preexisting conditions, you *might* be able to find a health insurance policy for $100 a month, at 23, with NO maternity benefits, and a $5000 deductible (which means, you pay the first $5K of medical bills every year).
20% coinsurance, is NORMAL. Most people have 20% or 30% coinsurance.
Plus, not all companies write coverage in all states.
You need to talk to someone LOCAL with experience - a LOCAL health insurance broker. He'll know which state you live in, what the state laws are (ie, do they HAVE to accept you at a higher rate, or can they flat out decline to take you?), and give you an idea what a REALISTIC price is going to be for your insurance.
In MOST states, you'd flat out be declined for coverage, or have the heart condition EXCLUDED from coverage, and STILL end up paying $300 a month or more for your coverage.
Your BEST BEST bet, is going to be looking for another job - yes, in this economy - because a group plan through your employer, is probably going to be the only thing you can afford.
So, look up a local agent. You can find one by zip code, at www.iiaba.net