solution for hair problems

Educate yourself regarding hairloss and understand hair loss in men and how to prevent it on www.hairstyle-everyday.net

It sounds like you are damaging your hair a lot with bleach, this is probably why it won't grow.  Some people's hair can grow just great without ever getting a trim, but its not the case for everyone, and especially those who use chemicals.  If you have splits, they need to be trimmed off or they just climb the hair, causing it to appear as if it doesn't grow.  This doesn't mean you have to cut all your hair off, just keep trimming it every so often until all the damage is gone.  Try to stop using chemicals on it as well, this will help greatly in helping you to keep it longer. 

As for a cut, if you want to do it yourself, blunt cut is the easiest.  If your hair is 4b, you might not like blunt cut, and you may like it better if it has layers just on the ends (say, long layers, only from the ears down).  This would be enough to taper it so it doesn't just stop in a straight line.  It is possible to cut and trim your hair yourself, you will just have to be patient with the learning process, and realize that if you're learning on your own, you will probably make some mistakes the first few times, and you may have to run to the salon to get help in fixing it.  You will be able to do it eventually though with practice.  Cut much less than you need cut so you will have some leeway when you are getting it even.  Have a friend with you to help, one your trust who doesn't want to hack all your hair off, but cares how you feel about it.

A side note, the salon should never convince you to cut all your hair off if that's not what you want.  They can tell you its damaged till the cows come home, but they can't cut it unless you tell them to.  If you wind up going back there, specify an amount you want cut (like, say, an inch), and watch them like a hawk and don't let them cut more than that, or convince you that's what you need if its not what you want.