I have 2 scratch accounts- one from when i was in primary school and one from high school. is there an way to merge them into one account and have one account access all projects etc?

Edit- the two accounts are this one and Cobaltduck , if that helps.

No, sorry. However, if you'd like all the projects on the same account, simply download and upload them.
Go to the editor, press “File v”, click “Download to my Computer” or whatever it says. Save as normal. In your other account, create a brand new project, press “File v”, click “Upload” or whatever it says, and upload as normal.