vaginapagina | Dildos to solve painful vaginal sex?

Whenever I have vaginal sex, whatever the position, it feels painful around the entrance of my vagina; not to say I don't enjoy it but that there seems always to be some pain of an almost stinging sort which prevents me from carrying on for as long as we otherwise would. It has been becoming more of an issue recently because I am so afraid of vaginal sex being disappointing or cut short that I have found myself avoiding it entirely.

I have been having sex for 3 years with one partner (I am also his first). I am on the pill but I don't think it is a case of lack of libido or lubrication; we have always had extensive foreplay and have tried a variety of (non-glycerin) lubes. I have had yeasties in the past but both my boyfriend and I have used yoghurt and canesten to treat them so I don't think its a current problem.

I have been considering buying a dildo/internal vibrator as I think this way I could 'practise' and acclimatise my body to being penetrated. (I think a toy might allow for short but frequent attempts that as I am in a long distance relationship sex cannot) I have also wondered whether it is possible that there could be 'remnants' of my hymen that are stretched but not broken? (I know this sounds implausible but I am really searching here)

Does anybody have any recommendations for suitable toys? (I live in the UK but would consider ordering online although I don't want anything too expensive)

Also, any other ideas on possible causes / solutions to painful sex.