When I log in I get someone els's account. How to I delete this and get back to my own account?

https://help.instagram.com/370452623149242

Quoting from link above:

How do I temporarily disable my account?
How do I delete my account?
When you delete your account, your profile, photos, videos, comments, likes and followers will be permanently removed. If you'd just like to take a break, you can temporarily disable your account instead.
After you delete your account, you can't sign up again with the same username or add that username to another account, and we can't reactivate deleted accounts.
To permanently delete your account:

1. Go to the Delete Your Account page. If you're not logged into Instagram on the web, you'll be asked to log in first. You can't delete your account from within the Instagram app.
2. Select an option from the drop-down menu next to Why are you deleting your account? and re-enter your password. The option to permanently delete your account will only appear after you've selected a reason from the menu.
3. Click or tap Permanently delete my account.

If you'd like to delete a different account, click the username in the top-right of the Delete Your Account page, tap/click on next to username and select Log Out. Log back in as the account you want to delete and follow the directions above.
For security reasons, we can't delete an account for you. You'll need to be able to log into your account to delete it. If you can't remember your password or username, see some tips for logging in.

unless you login to it you wont be able to find it. Usually it isnt deleted, only deactivated until someone logs back into the account again

What account are you talking about - Facebook or something else? Just log into your account and delete the posts / photos.

Hello,The easiest way to cancel your Craigslist account is to let it expire - log in, delete all of your postings and drafts and then wait. You could change your email to a non-existent address, but that's not advisable, since someone could get into your account and start posting ads. Without the ability to get back into your account to delete them or get responses from the Craigslist help desk, deleting your hacked account becomes more difficult.
Here is website you can read to give you more info.
Please rate my answer, Thank you.
How to Cancel an Account on Craigslist

The only way to delete it would be to log back into the non business FB account (when you're logging back in, it reactivates the account). After that, you want to go back and delete the business account.

Hi!
Dear you are trying to install photoshop from a USER ACCOUNT that do not have appropraite privileges to install a software.
Ask the System administrator to install it for you.
But if you are not on a company pc or a shared pc then try these steps
1> Log on to your account
2> then Log off
3> After logging off a blue screen will appear (called log on screen). press Ctrl+Alt+Delete (press delete button 2 times while holding the Ctrl and Alt keys).
4> Another screen will appear. There in the username field enter the words "Administrator" and leave the password field blank. Then press ENTER key.
You'll be logged on as administrator (if someone didn't have set a password for the admin account. About 75% people don't set it)
5> Now you can install the software or you may also change the type of your account from LOCAL USER to ADMINISTRATOR ACCOUNT by visting Control Panel

If the problem persist come back with the results of above steps.
thanks

clear the cache of your browser. delete the history & try again logging in facebook.

Hi,

To log out u need to go to the account button on the top right, then click log out. Once u do that it should take you back to the login page where your login information will be saved. Just uncheck the save my password box and have someone else log in.

Hope this helps you out,
Joe

It is very possible that someone else has gotten into your account some how. Be that you left your account logged in at a place where someone was able to get to it after you got up or someone just hacked your account.

I highly suggest changing your password and your hint question on your account.

please mark this fixya if it helps.