Hi,
There are three possibly easier options:
1. Get a lift or walk down to Coopers Green. Get a number 29 bus to Lewes (longish walk from the bus to the station) and then a direct train to East Croydon.
2. Get a lift or walk down to Coopers Green. Get a number 29 bus to Tunbridge Wells (short walk from the bus to the station) and then trains to East Croydon.
3. As mentioned by
telstarbox get a taxi to Haywards Heath.
The area's road network does not allow you to quickly follow the railway and bus going to/near all the stations from Crowborough to Purley would take ages.
Cheers,
Mr Toad