Great work on the weight loss! It is so difficult, and you should be proud. If you are motivated to lose more weight, you would set yourself up for the best result possible. Even if not, you can certainly be helped at your size. I would consider starting with a tummy tuck and breast lift (aka mommy makeover). You could certainly consider adding an implant to the breast lift if you would like to be bigger. Another option to consider is an arm lift. At a second operation, you may want to consider a bra roll excision and a BBL. Obviously, this is a pretty extensive plan and could be tailored. Most importantly, you have made great strides in leading a healthier life, and that is amazing!
So the real answer is...that it depends. If your priority is a "bikini body" then a tummy tuck with lipo of the flanks and bra roll would be your biggest bang for your buck. You could certainly use a breast lift, but if the reality is that a good bikini top may disguise things sufficiently for you. If you were looking for the best overall result, I would recommend a tummy tuck and a breast lift (aka tummy tuck) and the lipo discussed above. You could also consider fat transfer to the lateral buttock to round out a little at the same time.
Unfortunately, asymmetry following radiation is an extremely common and challenging issue. The irradiated breast tends to be higher and to have tighter skin. While at the exchange for implants, your surgeon will almost certainly improve your symmetry, this is likely to become a recurrent and worsening issue. Note the you have significantly less skin from the nipple to the fold on the left when compared to the right (unless I'm mixing up sides in the pic). This means that breast will never have quite as natural a "hang" as the non-irradiated breast. For my patients, I recommend converting to a diep flap reconstruction. I understand that this may be daunting for some patients, but will over the long run result in a much better outcome.
You need to see your plastic surgeon ASAP. Unfortunately, implants this badly infected usually have to be removed. I'm sorry you are going through this, but don't despair. Breast reconstruction is often a journey, but there are plastic surgeons that can help you get where you want to be.
Please don't! Any surgery at this point puts you at risk for miscarriage or the fetus developing birth defects. Do this once you are not pregnant.