Plateaus happen to most people during weight loss. The body does have setpoints which can be difficult to break through.
It might be time to re-evaluate your plan. Change things up a bit, or make sure that you are really following your plan. Sometimes plateaus are a result of becoming just a tiny bit lax on portions, like having a few bites of this here, and an eyeballed portion of something there.
Tightening up the discipline may be all you need.
Also - if you have been exercising, change what you are doing. The body gets used to exercise and you won't burn as many calories doing the same thing as it becomes more efficient. You should change it up every 6-8 weeks or so.
And as for loose skin, it's likely that you will have some. Those of us losing large amounts of weight have to deal with that. You may genetically be lucky.
I have some loose skin, but I would rather have that than the 100 pounds back.