Instead of the adjustments you've made, try starting with event normalization. Right-mouse-button click on the audio clip and from the popup menu choose Switches / Normalize. This will find the loudest peak in that event and raise it to 0dB, bringing the rest of the volume up with it. So if the loudest peak is -25dB then the whole clip will be raised 25dB.

Of course, volume slider + fx plugin + envelope already gives you 38dB boost and if your clip is still quiet after that then there may not be enough signal to get a good sound out of it.

Ideally a noise reduction plugin would be a good thing to try. If you don't have that then some EQ might help. For example, if the track is mostly spoken voice then you can try cutting out everything below about 250Hz and above 1.5KHz. This will get rid of the noise outside the primary vocal range without cutting the voice much. It may sound tinny, but it may be clearer and less objectionable.