YANBU
For those worried about the economy and Corbyn, have a read of the Institute for Financial Studies' analysis of the manifestos. They have plenty of issues with Corbyn's manifesto (mainly the level of corporation tax, which they think will be bad for business and therefore everybody). However, they think the Conservative manifesto is basically unaffordable and that promising to freeze taxes is a very dangerous idea, which will probably result in us going into debt.
"It is part of a fundamentally damaging narrative – that we can have the public services we want, with more money for health and pensions and schools – without paying for them. We can’t."
Yes, that's the Conservatives they're taking about, not Labour.
www.ifs.org.uk/election/2019/article/conservative-manifesto-an-initial-reaction-from-ifs-researchers
Re: the economy, the IFS are very clear that Brexit is the worst-case scenario (particularly a no-deal Brexit, but Brexit with a deal based on Johnson's withdrawal agreement) and that a Labour government is therefore best for the economy. Crucially, their ideal scenario would be a Labour minority coalition government, which is able to stop Brexit but not able to enact the most expensive of its manifesto promises (which they agree are not great for the economy).
Revoking Brexit would lead to the best economic outcome. We assume this would require a Labour-led government which, as well as revoking Brexit, would also implement significant tax and spending increases, an overall fiscal loosening and some tightening of labour market regulations. Interest rates would also rise more quickly. This might result in growth of 2% a year. Crucially, this scenario involves a Labour-led coalition rather than a majority Labour government.
www.ifs.org.uk/publications/14421
So yes. If you care at all about public spending and the economy, don't vote Tory.