ok ive been playing guitar for 4 years

i cant play solos for the life of me especially the revese runs (from high e down) , what can i do to help this , ive been practicing everything with a metronome , but i cant do it , i play metal leads, (like Trivium/All that Remains ect)i can play going from low D (im in Drop D) to high e but never high e to low d runs ..

All you can really do is practice. There is no secret way to get better at something.

Start slow and don't speed up until you can do your decending run at that speed.

I used to have the same problem. Ascending is a lot easier than decending, IMO. Just gotta keep at it.
Jackson RR24M - EMG ALX w/ ABQ installed
Ibanez Xiphos - stock
LTD Alexi 600 - stock
Ibanex RG - Tone Zone(bridge), PAF Pro(neck)
Blackstar HT-20H
Fulltone OCD
MXR 10 Band EQ
i can play both, but for some reason, i can play like 20-40bpm faster, going down

Ibanez RG7621
Ibanez RG121
put your fingers down before you use them
for example if your moving from b to g and the notes you are going to play on g are 10, 9, and 7, in that order, put down 10 and 9 at the same time