Quick weight loss on ANY form of diet, including low fat & low cal, can lead to hair loss. The follicles kind of 'shut down' for a while. But they do come back and begin to regrow hairs. Don't worry.

If you do a search here, using the above, search for "hair AND loss". There are threads that talk about this and recommend which supplements will support the regrowth.

How about eating more small meals instead of trying to eat a 'whole dinner'. A snack sized portion of protein plus some veggies or salad would do.

Congratulations on losing so well.