Offset when trying to convert square to triangular wave
That's the classic problem you get when trying to drive an integrator from a square wave.

The integrator's output will drift towards one supply or the other and may eventually saturate because:-

1) Square wave is not perfectly symmetrical (square). The saturation limits for the square wave generator are not symmetrical.

2) The integrator op amp has input offset voltage and input bias currents.

You can't use a polarised cap because it is being to charged to both polarities. Use a non-polarised cap or keep cap value lower and use a non-electrolytic.

Below is a favoured way of generating a triangle wave. It uses a non-inverting schmitt trigger driving an integrator.

Triangle wave output amplitude is set by ratio of R1 to R2.

Frequency is set by R3*C1 time constant.