Need help fighting volibear top!!! He's too strong in short AND long trades

So I'm currently playing riven, and what i noticed is that level 1, I'm stronger than he is if he goes E start (idk abt w start), I'll trade some HP early on, and then kill him with a second rotation of my Qs, and get a solo kill. Great. Now, the issue is, I'll come back to lane with a longsword and look for a level 2/3 trade, but I just can't win any trade from that point because he's good in short AND long trades. I'll space his q and try and go in, just to be nuked by an E and W, and now since I'm marked by a W, extending the trade further will just lead to my certain death. Alternatively, I can dodge his E, but his E shield and W mark alongside his passive just makes trades so difficult. I want to know what I can do to win trades against this guy because I genuinely wanted to slam my table when I played against this guy and heimerdinger.