Take a look around you at the rest of your team, spearmen have a secondary weapon for CQC. What you are experiencing is simply reality. I use a Bo staff (6ft) in martial arts and obviously if you have allowed the enemy to close within half the length, your tactics have to change. My Sensei always says " you have six feet of attack range, use it!". In the game your only real options when your opponent is right close, is bash if your pike or spear has that or go to a sword,axe or mace. Watch your AI units, if their opponent gets too close, they back up when using spears or they go to their secondary weapon.
My characture in the game mirrors my training in real life, I have tools for most scenarios. My battlefield loadout consists of a Bardiche(axe), A balanced heavy lance(spear), a strong bow and a large bag of kergit or Bodkin arrows. Of course I'm mounted when I start out, but if my opponent isn't sporting too many mounted units, I usually like to dismount my team and get down and dirty with them. For sieges, I lose the lance and go with a second quiver of arrows. In the game as with RL, focusing too heavy on one skill or weapon is a liability. At level thirty I'm sitting at 5 skill points for strike, draw, riding and athletics and the rest of the skills that are relevant like leadership stuff have what ever was left over. Shield is at zero as I have one but dont use it anyway, I used to use it in sieges before I got decent at archery.
Bottom line is this, you want to be a spearman? Great but that doesnt mean that should be the only weapon you have or be good at. Start attending the tournaments, you'll develop your proficiencies in different weapons and make decent coin while doing so(assuming you bet on yourself and win).