You should prolly read the sticky on "How to Bulk", then put together a diet of your own. If you truely are a hardgainer, you may need 4000+cals a day. But by the sounds of it, maybe you really arent, you just think your eating enough but really arent because you arent keeping a log of it. Keeping a log of that AND your training are very important tools.

After doing that, you should post up your diet and routine for critiqueing.