Question regarding freelance work, I think my previous employer is taking advantage of me.

I recently changed jobs and provided my employer with two weeks' notice. At the time, I had three projects while also training another employee.

Because I was focused on training a colleague to take over after me, I didn't have enough time to complete the three ongoing projects before leaving. My employer asked if I would be willing to continue working as a freelancer, particularly to finish the remaining projects. I agreed and may have accepted the same hourly rate, but the discussion was very brief, verbal, and very informal, as I was preparing to leave.

However, I did not fully consider that, as a freelancer, I would be responsible for paying my own employment taxes. I would effectively be earning less when I was previously employed by them.

Today, after completing one of the projects and being paid the same rate, I requested an increase by 1.5x to account for these additional costs.

My former employer agreed to the increase, but only after I completed the remaining two projects because they are considered "ongoing."

One of the projects also appears to be inactive. The manager seemed unwilling to spend money on the required system upgrade, and I could not proceed without his approval. I find it hard to think that's "ongoing" when I've been waiting for a month for his approval.

Is waiting to complete the remaining two project before the rate increase reasonable? I actually think there will be no more projects after the two.

Is it also reasonable to think a project is still "ongoing" after no movement and commitment? I tried to ask him if he wanted to continue the project, and been ignored multiple times. All of a sudden, he gave his approval to proceed.