Sidebar main menu

Hi,

I used a code found on this forum and made my right sidebar main menu sticky on desktop.
I also fixed my mobile header to be sticky.
this is my code:
@media only screen and (min-width: 768px) {
.html_header_sidebar #top #header.av_always_sticky {
right: 0;
}
.html_header_left #main {
margin-left: auto;
}

.html_header_sidebar #header .av-main-nav {
text-align: left;
}

.html_header_sidebar #top #header {
position:fixed!important;
width: 300px;
position: absolute;
min-height: 100%;
border-bottom: none;
}
}

@media only screen and (max-width: 989px) {
.responsive #top #main {
margin-top: 82px;
}
.responsive #top #wrap_all #header {
position: fixed;
}
#top .av_header_transparency .header_bg {
background-color: #ffffff;
}
}

@media only screen and (max-width: 767px) {
#top .av_header_transparency #header_meta {
background: blue;
box-shadow: none;
border-bottom: 1px solid rgba(255,255,255,0.25);
}

here are my problems:

1. The menu is sticky, but not “Sticky if Sidebar is smaller than the screen height, scroll otherwise”. and on smaller desktop screens it can’t be scroll down.
2. For some reason, the code added a large pudding on both sides of the main content.

can you pls hlpe me fix both of those problams?
Thanks so much!