Next you'd have an LFO generator. This is a low frequency oscillator that like the other oscillator produces a waveform but this waveform is too low in frequency to hear. It instead modulates the audio waveforms. It's controlled typically by what is called a modulation wheel. It's a wheel on the far left of the keyboard. There's two of them typically, the one on the far left is used to bend the pitch and the one on the right of it is used to modulate the sound via the LFO. Just like your audio oscillators the LFO will have a controller to switch between the different types of waveforms it produces. The LFO can typically be patched to modulate either the pitch (oscillators) or the volume or the frequency. So you can have a patch point here.
Next we'll have the real time frequency filter. This filter can usually be set to either a Low Pass filter (let's the lower frequencies pass through), High Pass filter (let's the high frequencies through) or a Band Pass filter (lets frequencies in a set band in the middle pass through). There will be a knob that controls the cut off and a knob that controls the resonance. There can be a patch point here.
Finally you might have an effects section where things like reverb, chorus, phase, flange, delay are applied to the sound. There can be a patch point here too.
The synthesizer you made is all patch points but they come and go to nothing. There's no function for them. You need more knobs and fewer patch points on your synth. Layout your synth in sections. Have you oscillator controls in one area, envelope controls in another, LFO controls etc. etc.