Thanks for asking your questions! Bonding would be a low-cost, low-impact solution for you. However, it would most likely last only a few years and would discolor. A more long term and high impact solution would involve orthodontics (with either clear aligners or braces) then ceramic veneers. The difference in cost is significant (a few hundred versus a few thousand) but so are the results.
Very sorry to hear that you are having trouble with your tooth. It sounds like part of the tooth has broken beyond the crown part and a dentist will need to fix it for you. The least expensive option would be to find a dentist with a good reputation who offers an in-house discount plan. Many dentists are starting to help non-insured patients with low-cost, preventative oriented dental plans that provide discounts on procedures like crowns.
Sometimes when a tooth is traumatized (as in smashed) it can cause the nerve inside the tooth to die. However, this dying process doesn't always cause immediate pain - it can take a few days for the pain to set in. I do not believe the pain is from the bonding procedure. Contact your dentist immediately and tell them what your symptoms are so you can avoid further discomfort.
Sometimes when a crown or filling is placed, there is not enough "insulation" between the nerve and the crown/filling to allow the nerve to heal. How much "insulation" a tooth needs to heal is very person-dependent... I've done crowns within 0.1mm of a nerve and the patient has been fine, but others have a good 2mm of space and they need root canals. It sounds like your dentist was being conservative and trying to save you the cost of the root canal hoping you wouldn't need it. It's often impossible for the dentist to predict whether your tooth will heal properly or will need a root canal.
It looks like your lateral teeth (the ones next to the ones that bother you) are pushed in, making your (beautiful) front teeth look way bigger. With simple Invisalign treatment, your dentist can move those lateral teeth forward, push the front bothersome teeth back, and possibly reduce the size of your front teeth slightly to give you a much more balanced appearance. I think you will love the results!
