Do I need to go smaller? 470 cc extra high silicone implants for a year and half (A cup before) and they are uncomfortable.

Although your breasts look very reasonable, if you find them uncomfortable, downsizing and changing to a lower profile would certainly be an option.  This is usually a fairly straightforward surgery and in your situation, you would probably not need to make major pocket adjustments.  If you wanted to reduce projection while maintaining your base width, dropping down to a 400cc range high profile or a mid 300cc moderate profile would likely work (these are approximate answers since I don't know what brand you currently have). I would suggest that you see your original surgeon to discuss your concerns and come up with a final plan for revision if that is what you decide to do.  Every surgery has potential pros and cons, so you would need to assess these prior to making a final decision on whether to have surgery. Best of luck!

You will probably experience relief with a smaller, lower profile implant. The size you choose depends on the cup size you wish to be. In my practice, most patients request to be C/D cup size. Discuss this with your surgeon. Best wishes.

I am sorry to hear about your concerns after breast augmentation surgery.  

 My thoughts regarding the potential need for revisionary breast surgery:  I advise patients to carefully consider their degree of concern with the outcome of the initial breast surgery and weigh these concerns against the potential risks/complications associated with the planned revisionary breast surgery.   For example, if the patient is concerned about her breast appearance on a daily or frequent basis, it is likely that revisionary surgery will be helpful when it comes to improving her quality of life.  On the other hand, if the patient's degree of concern seems minor and/or she is  infrequently concerned about the areas of concern, I would recommend against revisionary  breast surgery.
 
 Keep in mind as you are thinking about your goals that adjustment of the breast implant pockets (capsule adjustments) may be necessary to achieve the outcome you are looking for.    

In other words, there may be other variables involved, besides just breast implant volume, that come into play when it comes to achieving the desired aesthetic outcome.

Generally speaking, the best online advice I can give to ladies who are considering revisionary (downsizing) breast augmentation surgery is:

1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.

2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or "down a cup size” or "C or D cup" or "significant change" etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup size may also be inaccurate. 

3. Once you feel you have communicated your goals clearly, allow your chosen plastic surgeon to work with you in determining the best plan to achieve your goals.
I hope this helps. Best wishes.