What JDR13 said, try to draw out one or two enemies at a time, that way the fight becomes more manageable. It's a Very Good Idea(tm) not to get mobbed, as that is easily curtains for Geralt in the early game. Use the Stun and Trap signs (can't remember their in-game names now — Aard and Yrden?) to give you some breathing room. E.g. against the Endrega Warriors and especially the Queens, the Trap sign is very good, allowing you to kill them relatively easily (at least on Normal).
In the early game it is very important
not to get hit, no matter what armor you have on, as some enemies don't need but few hits to kill Geralt. Dodge and roll; it's better to dodge and not get hit, than to hit an enemy and get hit in return. Also, I know it's obvious, but remember to use the Shield sign (Quen? Or was this Yrden? ) to protect you. It is a life-saver. And do not over-extend or over-stretch yourself, i.e. don't just buttonmash or wade in like Conan the Conquerer — get a few strikes in, roll away, maneuver, use a sign maybe, attack again, etc. And last but not least, know when it's time to flee. The tactic of Brave Sir Robin (
) is good if you find yourself in over your head. Run and live to fight another day. The early game is full of such situations.
Regarding the drowners, I can't remember specifically what I did, but I do remember they hit HARD. Use the Shield sign to protect you (or be very good at dodging, you do not want to get hit by them). Maneuver to get a good opening on one drowner and wail on it (with the shield still on). If you can stun it first, all the better, might even get an instant kill that way. After a few hits, retreat, dodge and roll. Repeat. When your shield runs out, retreat and run around keeping your distance from the drowners, wait for your "mana/stamina" to recharge. Recast Shield. And so on. Grit your teeth and persevere. It is doable.