Hi Alex,
That is a bit odd that your LCD is working fine but your digitizer isn't. On things like iPhones, they have separate connectors for the two, but yours is a combined connector that has both functions on it, so if it's a connector issue it's unusual for only one of those functions to be affected.
That being said, however, there's really not much else to check or fix. So at this point your best option is to open up the phone again and unplug the display connector. Of course you disconnected the battery first when you did your repair, right? Check both sides of the display connector with a magnifying glass for any debris or contaminants and also look for bent or broken pins. A bent pin can frequently be straightened with fine tip tweezers. While you have it open, check as much of the flex cable as you can for any damage.
Once you're done checking, plug the display back in, being careful to make sure it's fully seated in the connector; long plugs like that can flex and end up with one end not fully seated, so be sure it's all the way in. Reconnect the battery and see if the touch is working yet. If not, you may have to remove the screen again to examine the display's flex cable.
That's really about all you can do. If nothing has worked up to this point, then you may be looking at having to replace the screen to get it working again.