The same thing happened to me. I'd been buying my own health insurance since I sold my company in 2011. It cost me $83 per month. I'm in my early 30's and healthy. Only time I used it was for a sinus infection and annual check ups. Deductible was $3500 with max out of pocket of $11,000. Office co-pay's were $30, $50 for urgent care and drug coverage worked well enough for me. My last antibiotics cost me $20 co-pay. Then I was informed last fall my plan was not "ACA" compliant and would be cancelled at the end of last year.
So I went shopping on the exchange. The closest plan to what I had was a silver package. It was $280 a month. 3x what I was paying. That was more than I wanted to pay. So I looked at a "Bronze" plan. Still $156 a month and eventually what I selected. It had a $6000 a year deductible and $17,000 max out of pocket per year.
Then I actually had to use it for an Urgent care visit. Under my old plan, Urgent care was a $50 visit. Well it was $90 co-pay under my new plan. I was prescribed the same antibiotics as the previous time. Cost: $45 co-pay instead of $20.
Fortunately I got married and now on my Wife's company plan (although they're likely to pay the fine as it will be cheaper than providing insurance so not sure for how much longer). It was about the same as my bronze plan (~$180 per month to add me). But coverage is a hell of a lot better.