The possibility of y'er account being deleted is very slim. If ye were only gone f'er a few months, I'd say that y'er account is still out there. Now, is this forum account y'er using y'ers or y'er friends? If ye can log into y'er forum account then what the problem may be is a password/username typo.
Now, from what I 'ave been told, changing y'er password only changed the forum accounts password. This could be totally untrue, but if 'tis, then ye will be needing to get a email that gives ye y'er password. To be honest, I am just throwing this out there f'er the rare possibility that this be true-but I don't think this is the issue.
Does anyone else know y'er account details? A friend could 'ave possibly used the account and didn't tell ye, but did something against the rules and may 'ave gotten the account banned. Now, I will not go into this further, since we are not supposed to speak of bans or possible bans, but it could 'ave been what happened.
Are ye using the numpad when logging in? FH will not read the numpad, so if ye are using it, try using the numbers above the keyboard. Also, make sure y'er not using NumLock. This be a strange setting that will mess up y'er keyboard. If ye updated to Windows 10, this may be what happened since this be one of the glitches of the new update.
As stated above, messaging a staff member is a very good idea. If ye can't manage to fix this y'erself, a staff member could help considerably. They would definitely be able to track y'er account's whereabouts.