Well, firstly, if you're not enjoying or looking forward to the game, why play at all?
Secondly, just pick Cleric or Paladin ... I, personally, would recommend Cleric, and go with that.
Paladins are a lot of fun, IMO. They are hard to kill and can dish out some hurt to big baddies. If you are bored, go full paladin.
If you made a martially oriented cleric with high charisma, a 2 level dip into paladin isn't horrible to get a nice bonus to saves and if you aren't playing a controller cleric you probably didn't lose too much in the way of effectiveness, and are much much harder to eliminate with a single bad save roll.
If your cleric was low chr, or focused on spell casting directly against the opponents, it was probably a really bad move.
My advise is if you aren't happy with your character, talk to your GM. My guess is he would at least allow you to work in the standard retraining and quite possibly will allow you free retraining to make your character as you wish you had. Most GMs want their players to be happy and enjoy the game, and are quite willing to work with them to make that happen.
Pure healing isn't a great thing to focus on in the first place in Pathfinder. But if you want to actually do it effectively, the Oracle of Life multiclassed with the Paladin is a great way to do it. Google the Oradin. Giants in the playground has a sweet guide on it.
What Paladin has going for it as a healer is the ability to heal itself as a swift action, leaving your standard to attack, cast, or whatever else you may wish. The Oracle nets you solid synergy with the Charisma, and the Life mystery can get you a second channel pool and the life link, allowing you to sponge damage off allies to heal yourself.
If you really can't retrain, you need to make some tough decisions. Could you at least change your archetype? Because a third level in Paladin (Holy tactician) nets you an all day team work feat to your party, and Weals Champion gives them a modest attack buff. Combine Weals Champion, out flank, and a a buff like bless and you can get your party a +5 to hit or higher quickly.
Another thing to consider would be the Antagonize feat. That's one of the few reliable ways to ensure enemies don't ignore you. If you've got full plate and can swift heal yourself, you want the enemy attacking you rather than your glass cannon allies.
Ask the GM if you can swap out the levels.
I like the fighteric more than the cleradin, but otherwise I agree with Ciaran.
I made a similar decision with a character of mine. We had played up to third level in 3.5 and then converted to (Core) Pathfinder. As she had always been a bit of an Elvan battle Cleric I thought flipping to Paladin with the new rules would work well. We had a little flexibility with feats etc. from the GM so the idea of a Paladin with a Clerics buffing capabilities appealed.
I've taken Power Attack, Deadly Aim and Improved Initiative and I'm now at 3/3. If I buff it makes me quite an effective tank with reasonable damage though the 1d6 Lay on hands isn't brilliant at 6th level CRs, the one attack is also a pain. The main problems are the buffs are low level short term ones and the Paladin goodies are a little underwhelming at 3 levels behind the curve. I wouldn't do it the same way again now I have a better grounding in PFRPG but she just about works.