You'll get the Shroud skill later on which is a life saver. I think somebody already mentioned it but use a pot early on. Later you'll use shroud but in Brayflox i was having the same problems and i started using my first pot at 90% MP then i'll always have my pots off CD when i need a boost later on. And just don't overdo things though this can be hard with some groups. Use regen mostly on the DPS and make use of stoneskin to reduce damage and your healing output.

Later on you have less MP issues since you can use shroud at 90% then again at 70% then a pot at 90% and shroud again at 80% and so on. If you plan timings for mana regen over using it when things get desperate you should have no MP issues. Of course Bards in your party make your job easy since you can request Mage's Ballad from them to boost MP.