I changed the bulb on my right tail light brake light and the tail light comes on but the brake light part does not flash on the right hand side

I have had this car since is was brand new. It has approximately 56,600 miles on it. All regular servicing has been done. For two days after driving home from work (45 minute freeway drive at between 40 - 65 mph), I noticed that when I turned off my car and got out to go into my house, the car smelled like something was overheating or burning (on outside of car--couldn't smell it inside car). I checked fluid levels under the hood, and all was well. Day 3, I got into my car to go to work and neither the heater nor defroster work any more. Any suggestions as to what could possibly be wrong, and about how much I should expect it to cost? Called a local Honda dealer, and after asking me a few questions, they said to expect about $1,500 to repair it, but didn't specify exactly what they think is wrong with the car. I don't have that kind of cash.Anything this senior citizen can do to track down the problem and how many $ I will ultimately need for repair?Will I do more damage driving it?