You might find that the PG levels are quite high in the shop-bought juices.
I'm guessing you have an Ego/CE4 type set-up (the most common tank system for new converts). Though these are far better than the cigalikes, there is better kit out there that might be worth considering if you're determined to avoid retuning to the stinkies and give this vaping lark a chance.
Protank mini 2 and mini 3 are small tanks that perform exceptionally well, and are pretty good prices, even from UK vendors (myepack seem to be amongst the best priced).
They are a bit cheaper than the larger tanks, but arguably perform better than the full size protanks.
It's also worth spending a little more on some gourmet juices - many vendors offer a choice of PG/VG levels (based on taster requests, it seems most of us prefer 50/50, which is hard to find in larger manufacturers' wares). Corner shop (and many ecig stores) juices aren't very inspiring, but there are loads of really good online stores doing their own lines of juice that know their market much better.
I wouldn't necessarily advise you to look into making your own at the moment, given that you're struggling a bit to keep going, but if you do find some juices that help you get past it, you might want to think about making your own, then you can have any flavour, strength and PG/VG levels you like.