Take a look e.g. through this one:
http://forums.d2jsp.org/index.php?showtopic=24496799&f=74to get an idea about basic mechanisms, how to stat a character and so on.
To give you a very brief survey:
The main problem on your current character is that you did not upgrade your gear while you level.
Monsters are getting stronger the higher you climb, thus you need some upgrades that support your character.
Items are classified in tiers , higher tiers have e.g. higher basic damage and thus support you better.
At the start, you should begin basically with tier III items, not tier I or II as you currently use.
They all have no level requirements, but tier III items can have higher modifications and have e.g. higher basic damage on weapons.
Take this chart as a small example:
Code
---------------
| Basic Weapons |
--------------- Level Sword Axe Dagger
Weapon Quality Required Base Damage Base Damage Base Damage
(I) Rusted 0 1-10 5-6 4-7
(II) Copper 0 2-20 10-12 8-14
(III) Bronze 0 3-30 15-18 12-21
(IV) Iron 5 4-40 20-24 16-28
As a melee, look for the following mods on items at the start
Level 1:Tier III
Level 5: Tier IV
Level 10: Tier V
Weapon with enhanced effect ( 30-70ee should be very cheap still )
upgrade weapon every 5 levels.
Armour with 5-15 dexterity and/or 5-15 strength, 1 - 25+ life after kill, 1 - 5+ life per attack, 150+ max life,
eventually some ee ( increases defence, not your damage on armors )
Upgrade every 5-10 levels, depending on how many of these stats you find on an armor.
Charms with 5-15 dexterity and/or 5-15 strength, 1 - 25+ life after kill, 1 - 5+ life per attack, 150+ max life
If you find these mods on a tier III charm already, you can keep it till level 10 - 15+
The longer you play, the higher modifications are possible, meaning you can get more stats on an item for lower fg then the equivalent on a lower tier item,
since also the basic values rise, it is important to update your gear about every 5-10 levels later on.
Take this for orientation:

You can find more information on tiers and modifications here:
http://forums.d2jsp.org/index.php?showtopic=3827582&f=272