Treatment options: surgery - anterior approach; success rate depends on the surgeon; heaviness is secondary to the drooping lid; ptosis could become worse with age. From the first set of pictures, the levator function appears to be good. Examination and accurate measurements are important to the success of your third procedure. The contour of the left lid in both photographs shows the peak of the lid displaced laterally. This suggests that the medial side of the muscle is severely attenuated and that the axis of the muscle is angled toward the temporal side of the lid. Several factors make your ptosis challenging - scar tissue from previous surgery, shortening of the superior fornix and tarsus because of the F-S procedure, axis of the levator is shifted toward the lateral lid, potential intrinsic neural or muscular damage from hypotensive/ anaphylactic reactions (your eyes appear to be aligned and I'm presuming no diplopia). Your surgeon might consider releasing the lateral horn of the levator, and moving the insertion medially to get good lift and contour. This will avoid an S-shaped contour. Ptosis surgery can be successful even after multiple attempts by previous surgeons - even 5 or 6. After many years of practice and working with the aftermath of other surgeons' ventures in the lid, an experienced Oculoplastic surgeon will know exactly how to help your eyelid. Best wishes for the third, hopefully last, treatment!
Part of the problem is that eyelids need to heal and function at the same time. Part of the problem is that the tissues in eyelids that are ptotic are inherently structurally weak. For these reasons, all ptosis surgeries have a relatively high failure rate. Revisional ptosis surgery is challenging. I am no Fasanella fan-it destroys normal upper eyelid architecture by excising the tarsus. The revision rate for this procedure and the anterior levator aponeurosis ptosis procedure are about 30%. Surgeons are reluctant to revise anterior levator surgeries due to scaring in tissue planes. I have had success with this type of revision and I think it is far better than other options. Full thickness ptosis surgery is very destructive and I do not think it is a good option. I encourage you to try again with a new surgeon.
I am assuming you had an oculoplastic surgeon do these surgeries since they are the ones who are specialists in this. You have now had both an internal and external approach to fix this. The question now is how much scarring is there in the lid, and do the muscles work well enough to try and do another repair. You need to see an oculoplastic surgeon to evaluate the eyelid muscles and determine whether it is worth trying again. There are many excellent oculoplastic surgeons in CA so you should be able to get a good answer.
Ptosis can be a difficult problem. I cannot give you specific information without examining you. However, revision eyelid surgery may be possible, using a completely different technique than that you had. See following link.
Assuming that secondary causes of your ptosis have been excluded, it sounds like you may be in a difficult position. The problem here is that you have had a Fasanella-Servat Procedure. This is a destructive procedure which removes much of the internal stability of the eyelid and makes revision surgery extremely difficult and particularly prone to contour changes.
I have performed many cases like this with success, but not always. So this can still be fixed, but you must ensure that you have a very experienced oculoplastic surgeon to perform the next revision and be realistic about the outcomes.
I assume other causes of ptosis have been investigated such as myasthenia, orbital tumor, Horner's syndrome, enophthalmos... If the levator function is decent, a repeat levator resection is what I would do. Most ptosis surgery is successful but ptosis will surprise you every now an then. I have gotten my reoperation rate down to 5% or so over the years but I would rather do a blepharoplasty if I can get away with it.