If your tree is past it's best then throw it out>
IIRC four Christmases ago, we bought a tree from our usual local garden centre , it was £60. The branches were a bit wonky, lots of gaps, but yes you get the lovely smell but the needles 
So we got a nice ( if such a thing exists) fakey tree,it arrived about the 20th, so hastily assembled and decorated (I wasn't pleased, though, they need alot of time spent flouncing them )
The next two years though, I spent more time, put more lights on, and decorated every branch. It was lovely
and because it isn't real. it can go near the radiator if the lights are protected .
We do have an outdoor potted tree that has solar lights.
DH asked me last year if I wanted a real tree - I was sooo tempted but resisted.
When this one gets past it, I'll go back to real though.