Is my chin really weak? (photos)

Without an exam your question cannot be answered.  You will need to see an Oral/Maxillofacial surgeon to see if othognathic surgery, genioplasty or using an implant is best for your specific case. It should be noted that patients with severely weak jaws or abnormally functioning jaws may be better treated with other facial surgery (orthognathic surgery), although a chin augmentation may be an option at a later time. These patients should seek the advice of a plastic surgeon to determine which course is right for them. Here is some information to help you make this decision: Candidates for Chin Augmentation - Patients whose chin profiles are weak but have normally functioning jaws are candidates for Chin Augmentation. Many of these candidates have used injectable fillers in the past to strengthen the protrusion of their chins, but are looking for a permanent solution. If you are one of these patients, then you are a likely candidate for chin augmentation

It is difficult to assess based on the photos you provided here. Hence, I suggest beginning with an in-person consultation with a board certified plastic surgeon to discuss your options. During your initial examination, your #chin will be evaluated along with the neck and jawline. A weak #chin implies a lack of chin support for the skin along the neck line. In younger individuals a chin implant alone is usually all that is needed to improve the appearance of the neck. Subsequently, it will also improve the overall #balance of the face and can create the illusion of a smaller nose. As a stand-alone procedure, chin augmentation can be performed in the office under local #anesthesia. For individuals with signs of #aging in the neck, a chin implant added to one of the recommended procedures above, will provide optimal results. Liposuction under the chin is also another option your doctor can discuss. If you are not a candidate for chin or neck rejuvenation at the time of your #consultation, your board certified plastic surgeon can recommend alternatives to address your concern. 
However, there may be additional options to improve the appearance of your concern to improve the overall balance of your face. Such can be best evaluated in-person. Consulting with a board-certified plastic surgeon who specializes in #face, #neck and #chin procedures is important to ensure you are receiving the best advice, care, and surgical experience possible.

Thanks for your question and photos, 89asch.  Nothing substitutes for a consultation and in depth conversation of your desired appearance.  Having said that, there are some studies about facial proportion that provide guidance.  Often we look for the point where the nose takes off from the forehead, the point where the base of the nose joins the upper lip, and the point of greatest projection of the chin to align. Your photos do suggest that you may benefit from a more projecting chin.  Know that before committing to a chin implant you could consider using some fillers to provide more chin projection and see how your appearance is affected.  Consider meeting with a BCPS to discuss your options.