heat & blower

i would start with the heater control unit, also check for a vaccuum leak in the engine bay, its a hard plastic line that will crack and break

Only blowing on defrost probably means that the vacuum line that controls the door has a leak or is broken. It comes off the line that runs under the wiper cowl against the firewall in the engine bay.... it's a small line about 1/4 diameter that goes through the firewall. It may have come loose from the switch itself. As for the lack of heat you probably need the heater core back-flushed, any shop can do it, or you can do it yourself with a garden hose. Only takes about 10-15 mins very easy