Was my incisions done too close to the medial canthus? (photo)

If is most definitely not going to help your current situation.  Any one offering it to you now is simply looking to take advantage of your current distress to talk you into a service you don't need.  It is far too early what you might need for these eyelids.  The "webbing" is related to swelling.  I recommend patience here to allow the swelling to resolve.  I think you have 3 to 4 months of healing ahead of you before you know what type of result you have had and what your issues are.  Upper eyelid ptosis is the most significant concern here.  Hopefully with healing, it resolves.

Tough to tell much from this picture, but it doesn't look like you have much webbing.  If an incision is continued medially this can increase the risk of webbing.  If you get a true web, some injections of kenalog with 5-FU will often help to soften and flatten the scar.  If the web is pronounced and doesn't respond to the injections then a z plasty could be done.   

Hi:
Even though you are 3 weeks after upper lid blepharoplasty, from the photo it looks like you still have some swelling and bruising. If you develop webbing, it would be best to wait 3-6 months before undergoing additional surgery, such as z-plasty, Time will allow the incisions and inflammation to stabilize. In the meantime, your surgeon may suggest steroid ointments to the incisions, massage, or Kenalog  injections,with or without 5FU. Hopefully with these measures you will not need additional surgery!

From your pictures you are still early in your healing.  It doesn't appear to show webbing at this point, which is a good sign.  Webbing can occur if the incisions are taken too medial or if extensive cautery was needed medially secondary to excessive bleeding.  Some have webbing even before surgery.  If webbing develops then massage, steroid/5FU injections, and Z-plasty can help if not eliminate the webbing.  Be in contact with your surgeon.  Best regards towards your healing.