A merge needs to be done *from* development *to* your_branch. To do so, follow the steps:
1- Before any merge attempt, try to save/backup your code. The way we are working, there is no problem if you commit and push a "broken" code to the cloud. Just make sure your are in your branch and perform the push.
2- Be sure you are in your branch:
$ git checkout my_branch
3- Be sure your branch is updated
$ git pull origin my_branch
4- Proceed the merge:
$git merge remotes/origin/development
Git will automatically checkout and add files with no conflicts. In conflicted files, it will checkout and modify files showing chunk of code from both sides (development and your branch). Changes will be saved in the files and you need to edit file by file and dictate what is the right code in each file.
To get a list of conflicted files use:
$ git diff --name-only --diff-filter=U