Tretinoin is No Longer Available in the UK Due to Janssen Cilag Discontinuing Stocks, What Can I Replace It With?

Please help guys. Tretinoin has been discontinued in the UK, what can I use instead of? It's for mild acne and acne scarring, and also wrinkles. I really love tretinoin and I'm devastated its gone. I've found Tazorac on line but my GP and Chemist could not find it, is it an american thing? Is differin any good? Please, please, please help, it has taken me years to get my skin to the level it is and really don't want to return to the state it previously was. Retin A was a godsend...