Voltage ramp with split power supply
I simulated my circuit, and even though I did not put a DAC, I think its pretty accurate simulation:

My output (on R8) goes to -2.5V as I wanted it to be.

And on +2.5V as I want it to be.
I also figured out I do not need the AMP2 (The differencial op amp). I can have +2.5 and -2.5 directly from DAC: