Although much of your post-op swelling has resolved by 2 months post-op, your scars are still pink and immature, and your abdominal tissues still have some lymphatic swelling that will gradually resolve over several more months. However, this swelling is relatively minor compared to the degree of residual protrusion you are showing in your photographs.
This can be due to several factors, including one commonly not considered by patients--residual intra-abdominal fatty tissue. In most tummy tuck patients, the abdominal skin is loose and the muscles stretched (usually from pregnancy, but also after massive weight loss or other causes), and a tummy tuck will tighten the muscles (plication or muslce "repair") and remove the excess skin. This also involves a new skin opening for the umbilicus (causing the scar you and most patients have with a full tummy tuck) and the hip-to-hip scar. The abdomen is flatter because of the tighter abdominal "container," as well as the tightened skin/fat flaps. The thinner you were pre-op, the thinner the subcutaneous fat layer beneath the skin.
Let's say, however, we have a patient who carries a lot of "extra" weight not just in her subQ fat, but also in her abdominal contents (mesenteric and omental fat) and has a rounded or protruding belly on this basis. A tummy tuck in this kind of patient will end up failing to create a significantly-flatter abdomen because of the intra-abdominal contents trying to be squeezed into a tighter (muscle-tightened) abdominal container. Sort of like trying to put a 12-gallon head into a 10-gallon hat! It won't fit, and the same problem occurs with tummy tuck patients with excess INSIDE fat--either the muscle repair tears through, or the attempt to tighten the abdominal wall just doesn't work that well against the tension of the intra-abdominal contents. It does look as if you still have a bit of loose skin, but that is not the reason for your protruding abdomen.
It's either the scenario I discussed above regarding your "inside-the-abdomen" contents (which your surgeon should have addressed in the pre-operative evaluation, and discussed with his/her recommendations), or it's loss of plication sutures (tearing through). Or perhaps both:(
You could still have some excess skin and fat, but this degree of protrusion is usually one of the two things noted above.
In a few patients, constipation and/or bloating can cause this degree of protrusion, but you would certainly be aware of difficulties in this department, and then the "fix" is relatively easy.
Seroma is unlikely at 8 weeks, but this too is something your surgeon can easily diagnose and treat.
Bottom line--go see your surgeon and see what is going on. It would be wise for you to see your pre-operative photographs as well. Ask your surgeon or his nurse to see them. This may help you understand the answer! Best wishes!