AC not blowing cold
Hey, so a few days ago my ac stopped blowing cold air. The condenser is running. I replaced the fan about 2 years ago, it has a new filter, cleaned the cold air returns, and I cleaned out the fins on the condenser (some are a little bent but the fan is pushing air pretty well) I tried resetting the system electrically to no avail. The copper lines aren't frozen up, theres no physical way to access the drip tray, but I know that the drain line is plugged and that the local hvac company just wants to replace everything. Its been plugged for years and while it has caused water damage, the ac was still working.
The past couple weeks have been pretty warm (above 0 overnight.) And we've been running the ac for about a week and a bit now. And this just started a couple days ago.
My knowledge in hvac and ac is very limited (specifically i only know automotive/semi truck ac systems being a heavy duty mechanic) to me it feels like im losing refrigerant but im wondering if theres a simpler explanation for this that im overlooking.
The unit in my house is an old lennox furnace/ac system from 1988.
Any help would be appreciated.