How long until I stop feeling this way?

It only stops until you stop expecting that it'll happen. Sometimes it's not the how long that matters, but the steps you take to stop feeling the way you do.

Unfortunately, there is no set time frame on how long it takes to go through certain "feelings". No matter what the situation, let yourself feel the emotions, talk to someone, make sure you are not bottling them all up inside, that can tend to make things worse. If it's grief you're dealing with, let yourself grieve. If it's depression you're dealing with, let yourself be sad. But also make sure you're working your way towards a better place, don't get "stuck" in these places, it can be hard to do, so sometimes you will need to push yourself to move forward (even if it's just a centimeter per day, you're still MOVING!) Love yourself....let yourself feel!

Everyone is different. In time, you can work towards finding solutions that will best benefit you. Once you find these, healing is right around the corner.

I believe this is a question you have to answer yourself. Personally, I believe you will stop feeling the way you do when you make change. Only you have the power to change the way you feel. Use the feelings you have to motivate you to better yourself.

no one knows this. give yourself time and maybe some day soon you will realize the upsetting feeling is no longer there.

With a lot of things in life your look on things really decide the results for you, if you look at it in a negative way then the feelings will last longer, the best way to stop feelings it to acknowledge them, understand why you feel them and move on from them

Honestly, it can take days, weeks, months, years even. But a good way to help yourself is just think positively. Do things in your life that help with this too.