While I was in hospital my new neighbour put up a gate at his end of the lane behind our cottages. This means there’s no longer room for me to get into my garage. According to my deeds he’s taken about ten extra yards of the lane, but the neighbour say’s he’s contacted the Land Registry and my title deeds aren’t worth the paper they’re written on.
Contrary to your neighbours opinion your title deeds are the ultimate authority concerning your property. You should ask a solicitor to look at them. It’s possible that your new neighbour is entitled to put up a gate, but if you’ve been using his section of the lane in order to reach your garage over a long period of years he may have great difficulty stopping you doing so now.