Hi. This isn't an expert opinion, but I hope it helps.
In general terms, drug treatments are:
SSRIs - Selective Seretonin Reuptake Inhibitors - increase the brain concentration of seretonin (a neurotransmitter). These include citalopram, escitalopram, fluoxetine, paroxetine (various posters have mentioned tradenames e.g. prozac = fluoxetine). They have various side-effects but what made one person feel really ill may be fine for you - or vice versa.
SNRA - Selective Noradrenaline Reuptake inhibitors i.e. Venlafaxine - this works on noradrenaline (neurotransmitter) as well as seretonin. Generally second line as a bit more effective than SSRIs.
TCAs - tricyclic antidepressants e.g. amitryptilline, clomipramine. Older drugs - still effective, but maybe more troublesome side effects - dry mouth, constipation, sleepiness (of course if you took two people, one might be happy with amitryptilline and not get on at all with sertraline). Part of the reason they are less used is that they are much more dangerous in overdose than SSRIs.
Some others, e.g. mirtazipine, lithium - if you're getting to this stage, then a psychiatrist would be very helpful - GPs certainly wouldn't be starting Lithium.
Non-drug treatments:
Cognitive Therapy: useful treatment if it is available where you live. Nothing like Freudian lying on a sofa talking about your parents. Actually very common sense e.g. challenging persistent negative thought patterns
e.g. all or nothing thinking: 'My daugher fell off the bed and banged her head whilst I was distracted. I'm a terrible mother.' Are mothers either all good or all bad? No-one's perfect but your daughter is loved, well fed, safe and is usually closely watched.'
thought-reading: they think I'm stupid' How can you tell what other people are thinking?
And so on. Provides you with a tool kit for dealing with life's stresses.
Counselling - some people find it helpful; I'm not up to date with the evidence, but I don't think the evidence base is all that good.
Various other psychological treatments.
If you'd like more information on a particular drug / side effects, I'll happily post it.
Having said all that, the drugs do all have side-effects, and most drugs can have serious ones sometimes. You said that you don't fit the typical pattern for depression. I'm not at all questioning that you are having difficulties, but it's important to make sure you are actually depressed before starting these treatments. If you're not confident about your GP's view that ADs aren't for you, then can you see another one? It's possible that he is right, but if that is so, it will be important for you to be confident of this, so you can try a different strategy. Sorry if this last bit sounds vague and even patronising; I'm not trying to be.