What went wrong with my rhinoplasty and what can or should be done to fix this? (photo)

The tip of your nose is still big, as you mentioned, and it sits low. Elevating the tip should help quite a bit.
The woman in the short video that I posted with this answer had the tip of her nose elevated and narrowed in her revision operation.
As is typical, too, the three-quarter and frontal views make the nose look even longer -- needing tip elevation -- than the profile views do.
The bump should come down, and all efforts at increasing symmetry of the nose as well.
If I may say, I don't understand the splint. It doesn't look as though it's designed to hold the nasal bones in a precise position, which is the purpose of a good splint.
I'd love for you to see some excellent professionally-designed morphs of what could possibly be done with your nose. Morphs could also help you identify what's bothering you, and help you set a goal for the rhinoplasty that's accurate for your tastes, and probably give you some optimism. From these photos, it seems that there is enough cartilage remaining in your nose to allow most of the desired changes to be possible. (Side note: in my opinion, morphs should always be done by the surgeon, or he should direct an assistant as she makes the morphs. Morphs should be made with a constant eye to what actually *can* be done in surgery, for that particular nose, and only the surgeon has that information and judgment.)
Remember that rhinoplasty is an exquisitely difficult operation to get right, and you should only have surgery if you are able to make yourself very confident in your surgeon's skills. The changes that your nose needs require advanced techniques, requiring skill that most plastic surgeons don't possess with expertise. For most noses, it's much better to not have surgery than to have inexpertly-performed surgery. Read my essay on how to stay out of trouble while selecting a rhinoplasty surgeon. And for those who have had previous surgery, it also discusses how to tell whether your first surgeon should be performing your revision.
Your nose is also a perfect example of why computer imaging is mandatory in rhinoplasty. You need to know exactly what the surgeon is planning to accomplish -- what features he thinks he can change, and by how much he thinks he can change them. I always email morphs to my online rhinoplasty consultations. When you see the surgeon's goals in the morphs, you'll know whether he has an eye for an attractive nose, and whether he shares your opinion of what constitutes an attractive nose. You'll also know whether the changes he proposes are large enough to be meaningful to you, and whether he understands your wishes enough to address all of your priorities. How would you ever get that figured out without the morphs?

Your nose can definitely be improved to correct both the size, position and width of your nose as well as the tip region. It is difficult to say what occurred with your first rhinoplasty. That being said there are basically two types of issues that require correction in rhinoplasty patients, errors of omission or errors of commission. Typically, when too much tissue is removed then this can result in saddling or collapse in certain parts of your nose like the lower third region below the bump. Errors of omission can occur when not enough tissue is removed in certain areas like the tip region or in the upper aspect of the nose leaving a more prominent hump. Even the best surgeons can have either of these occurrences as the typical revision rate is about 15%. Your options at this point are to go back to your original surgeon to see if he/she will do some additional work for you at a reduced or compensated charge. The other options is too see a board certified facial plastic surgeon in your area who has expertise in revision rhinoplasty procedures.

In person exam is essential, as well as reading op-report. Based on photos- it appears that -in the right hands-improvements can be achieved with Revision Rhinoplasty preferably performed through closed technique. Keep in mind that the first time is the best time. It's very important to select a qualified, experienced and skilled Rhinoplasty Surgeon.